Photodiode

Last updated
Photodiode
Fotodio.jpg
One Ge (top) and three Si (bottom) photodiodes
Type Passive, diode
Working principleConverts light into current
Pin configuration  anode and cathode
Electronic symbol
IEEE 315-1975 (1993) 8.5.4.1.svg

A photodiode is a semiconductor diode sensitive to photon radiation, such as visible light, infrared or ultraviolet radiation, X-rays and gamma rays. [1] Photodiode is a PN semiconductor material that produces current or voltage Photovoltaics when it absorbs photons Semiconductor Optoelectronics (Farhan Rana, Cornell University). The physics of electron excitation for photodiodes are similar to Photoconductivity typically implemented as a Photoresistor or as switches in Thyristor#Photothyristors. Photodiodes can be used for detection and measurement applications, or optimized for the generation of electrical power in solar cells. Photodiodes are used in a wide range of applications throughout the electromagnetic spectrum from IR, visible light, UV photocells to gamma ray spectrometers.

Contents

Principle of operation

A photodiode is a PIN structure or p–n junction. When a photon of sufficient energy strikes the diode, it creates an electronhole pair. This mechanism is also known as the inner photoelectric effect. If the absorption occurs in the junction's depletion region, or one diffusion length away from it, these carriers are swept from the junction by the built-in electric field of the depletion region. Thus holes move toward the anode, and electrons toward the cathode, and a photocurrent is produced. The total current through the photodiode is the sum of the dark current (current that is passed in the absence of light) and the photocurrent, so the dark current must be minimized to maximize the sensitivity of the device. [2]

To first order, for a given spectral distribution, the photocurrent is linearly proportional to the irradiance. [3]

Photovoltaic mode

I-V characteristic of a photodiode. The linear load lines represent the response of the external circuit: I=(Applied bias voltage-Diode voltage)/Total resistance. The points of intersection with the curves represent the actual current and voltage for a given bias, resistance and illumination. Photodiode operation.png
I-V characteristic of a photodiode. The linear load lines represent the response of the external circuit: I=(Applied bias voltage-Diode voltage)/Total resistance. The points of intersection with the curves represent the actual current and voltage for a given bias, resistance and illumination.

In photovoltaic mode (zero bias), photocurrent flows into the anode through a short circuit to the cathode. If the circuit is opened or has a load impedance, restricting the photocurrent out of the device, a voltage builds up in the direction that forward biases the diode, that is, anode positive with respect to cathode. If the circuit is shorted or the impedance is low, a forward current will consume all or some of the photocurrent. This mode exploits the photovoltaic effect, which is the basis for solar cells – a traditional solar cell is just a large area photodiode. For optimum power output, the photovoltaic cell will be operated at a voltage that causes only a small forward current compared to the photocurrent. [3]

Photoconductive mode

In photoconductive mode the diode is reverse biased, that is, with the cathode driven positive with respect to the anode. This reduces the response time because the additional reverse bias increases the width of the depletion layer, which decreases the junction's capacitance and increases the region with an electric field that will cause electrons to be quickly collected. The reverse bias also creates dark current without much change in the photocurrent.

Although this mode is faster, the photoconductive mode can exhibit more electronic noise due to dark current or avalanche effects. [4] The leakage current of a good PIN diode is so low (<1 nA) that the Johnson–Nyquist noise of the load resistance in a typical circuit often dominates.

Avalanche photodiodes are photodiodes with structure optimized for operating with high reverse bias, approaching the reverse breakdown voltage. This allows each photo-generated carrier to be multiplied by avalanche breakdown, resulting in internal gain within the photodiode, which increases the effective responsivity of the device. [5]

Electronic symbol for a phototransistor IEEE 315-1975 (1993) 8.6.16.svg
Electronic symbol for a phototransistor

A phototransistor is a light-sensitive transistor. A common type of phototransistor, the bipolar phototransistor, is in essence a bipolar transistor encased in a transparent case so that light can reach the base–collector junction . It was invented by John N. Shive (more famous for his wave machine) at Bell Labs in 1948 [6] :205 but it was not announced until 1950. [7] The electrons that are generated by photons in the base–collector junction are injected into the base, and this photodiode current is amplified by the transistor's current gain β (or hfe). If the base and collector leads are used and the emitter is left unconnected, the phototransistor becomes a photodiode. While phototransistors have a higher responsivity for light they are not able to detect low levels of light any better than photodiodes.[ citation needed ] Phototransistors also have significantly longer response times. Another type of phototransistor, the field-effect phototransistor (also known as photoFET), is a light-sensitive field-effect transistor. Unlike photobipolar transistors, photoFETs control drain-source current by creating a gate voltage.

A solaristor is a two-terminal gate-less phototransistor. A compact class of two-terminal phototransistors or solaristors have been demonstrated in 2018 by ICN2 researchers. The novel concept is a two-in-one power source plus transistor device that runs on solar energy by exploiting a memresistive effect in the flow of photogenerated carriers. [8]

Materials

The material used to make a photodiode is critical to defining its properties, because only photons with sufficient energy to excite electrons across the material's bandgap will produce significant photocurrents.

Materials commonly used to produce photodiodes are listed in the table below. [9]

Material Electromagnetic spectrum
wavelength range (nm)
Silicon 190–1100
Germanium 400–1700
Indium gallium arsenide 800–2600
Lead(II) sulfide <1000–3500
Mercury cadmium telluride 400–14000

Because of their greater bandgap, silicon-based photodiodes generate less noise than germanium-based photodiodes.

Binary materials, such as MoS2, and graphene emerged as new materials for the production of photodiodes. [10]

Unwanted and wanted photodiode effects

Any p–n junction, if illuminated, is potentially a photodiode. Semiconductor devices such as diodes, transistors and ICs contain p–n junctions, and will not function correctly if they are illuminated by unwanted light. [11] [12] This is avoided by encapsulating devices in opaque housings. If these housings are not completely opaque to high-energy radiation (ultraviolet, X-rays, gamma rays), diodes, transistors and ICs can malfunction [13] due to induced photo-currents. Background radiation from the packaging is also significant. [14] Radiation hardening mitigates these effects.

In some cases, the effect is actually wanted, for example to use LEDs as light-sensitive devices (see LED as light sensor) or even for energy harvesting, then sometimes called light-emitting and light-absorbing diodes (LEADs). [15]

Features

Response of a silicon photo diode vs wavelength of the incident light Response silicon photodiode.svg
Response of a silicon photo diode vs wavelength of the incident light

Critical performance parameters of a photodiode include spectral responsivity, dark current, response time and noise-equivalent power.

Spectral responsivity
The spectral responsivity is a ratio of the generated photocurrent to incident light power, expressed in A/W when used in photoconductive mode. The wavelength-dependence may also be expressed as a quantum efficiency or the ratio of the number of photogenerated carriers to incident photons which is a unitless quantity.
Dark current
The dark current is the current through the photodiode in the absence of light, when it is operated in photoconductive mode. The dark current includes photocurrent generated by background radiation and the saturation current of the semiconductor junction. Dark current must be accounted for by calibration if a photodiode is used to make an accurate optical power measurement, and it is also a source of noise when a photodiode is used in an optical communication system.
Response time
The response time is the time required for the detector to respond to an optical input. A photon absorbed by the semiconducting material will generate an electron–hole pair which will in turn start moving in the material under the effect of the electric field and thus generate a current. The finite duration of this current is known as the transit-time spread and can be evaluated by using Ramo's theorem. One can also show with this theorem that the total charge generated in the external circuit is e and not 2e as one might expect by the presence of the two carriers. Indeed, the integral of the current due to both electron and hole over time must be equal to e. The resistance and capacitance of the photodiode and the external circuitry give rise to another response time known as RC time constant (). This combination of R and C integrates the photoresponse over time and thus lengthens the impulse response of the photodiode. When used in an optical communication system, the response time determines the bandwidth available for signal modulation and thus data transmission.
Noise-equivalent power
Noise-equivalent power (NEP) is the minimum input optical power to generate photocurrent, equal to the rms noise current in a 1  hertz bandwidth. NEP is essentially the minimum detectable power. The related characteristic detectivity () is the inverse of NEP (1/NEP) and the specific detectivity () is the detectivity multiplied by the square root of the area () of the photodetector () for a 1 Hz bandwidth. The specific detectivity allows different systems to be compared independent of sensor area and system bandwidth; a higher detectivity value indicates a low-noise device or system. [16] Although it is traditional to give () in many catalogues as a measure of the diode's quality, in practice, it is hardly ever the key parameter.

When a photodiode is used in an optical communication system, all these parameters contribute to the sensitivity of the optical receiver which is the minimum input power required for the receiver to achieve a specified bit error rate .

Applications

P–n photodiodes are used in similar applications to other photodetectors, such as photoconductors, charge-coupled devices (CCD), and photomultiplier tubes. They may be used to generate an output which is dependent upon the illumination (analog for measurement), or to change the state of circuitry (digital, either for control and switching or for digital signal processing).

Photodiodes are used in consumer electronics devices such as compact disc players, smoke detectors, medical devices [17] and the receivers for infrared remote control devices used to control equipment from televisions to air conditioners. For many applications either photodiodes or photoconductors may be used. Either type of photosensor may be used for light measurement, as in camera light meters, or to respond to light levels, as in switching on street lighting after dark.

Photosensors of all types may be used to respond to incident light or to a source of light which is part of the same circuit or system. A photodiode is often combined into a single component with an emitter of light, usually a light-emitting diode (LED), either to detect the presence of a mechanical obstruction to the beam (slotted optical switch) or to couple two digital or analog circuits while maintaining extremely high electrical isolation between them, often for safety (optocoupler). The combination of LED and photodiode is also used in many sensor systems to characterize different types of products based on their optical absorbance.

Photodiodes are often used for accurate measurement of light intensity in science and industry. They generally have a more linear response than photoconductors.

They are also widely used in various medical applications, such as detectors for computed tomography (coupled with scintillators), instruments to analyze samples (immunoassay), and pulse oximeters.

PIN diodes are much faster and more sensitive than p–n junction diodes, and hence are often used for optical communications and in lighting regulation.

P–n photodiodes are not used to measure extremely low light intensities. Instead, if high sensitivity is needed, avalanche photodiodes, intensified charge-coupled devices or photomultiplier tubes are used for applications such as astronomy, spectroscopy, night vision equipment and laser rangefinding.

Comparison with photomultipliers

Advantages compared to photomultipliers: [18]

  1. Excellent linearity of output current as a function of incident light
  2. Spectral response from 190 nm to 1100 nm (silicon), longer wavelengths with other semiconductor materials
  3. Low noise
  4. Ruggedized to mechanical stress
  5. Low cost
  6. Compact and light weight
  7. Long lifetime
  8. High quantum efficiency, typically 60–80% [19]
  9. No high voltage required

Disadvantages compared to photomultipliers:

  1. Small area
  2. No internal gain (except avalanche photodiodes, but their gain is typically 102–103 compared to 105-108 for the photomultiplier)
  3. Much lower overall sensitivity
  4. Photon counting only possible with specially designed, usually cooled photodiodes, with special electronic circuits
  5. Response time for many designs is slower
  6. Latent effect

Pinned photodiode

The pinned photodiode (PPD) has a shallow implant (P+ or N+) in N-type or P-type diffusion layer, respectively, over a P-type or N-type (respectively) substrate layer, such that the intermediate diffusion layer can be fully depleted of majority carriers, like the base region of a bipolar junction transistor. The PPD (usually PNP) is used in CMOS active-pixel sensors; a precursor NPNP triple junction variant with the MOS buffer capacitor and the back-light illumination scheme with complete charge transfer and no image lag was invented by Sony in 1975. This scheme was widely used in many applications of charge transfer devices.

Early charge-coupled device image sensors suffered from shutter lag. This was largely explained with the re-invention of the pinned photodiode. [20] It was developed by Nobukazu Teranishi, Hiromitsu Shiraki and Yasuo Ishihara at NEC in 1980. [20] [21] Sony in 1975 recognized that lag can be eliminated if the signal carriers could be transferred from the photodiode to the CCD. This led to their invention of the pinned photodiode, a photodetector structure with low lag, low noise, high quantum efficiency and low dark current. [20] It was first publicly reported by Teranishi and Ishihara with A. Kohono, E. Oda and K. Arai in 1982, with the addition of an anti-blooming structure. [20] [22] The new photodetector structure invented by Sony in 1975, developed by NEC in 1982 by Kodak in 1984 was given the name "pinned photodiode" (PPD) by B.C. Burkey at Kodak in 1984. In 1987, the PPD began to be incorporated into most CCD sensors, becoming a fixture in consumer electronic video cameras and then digital still cameras. [20]

In 1994, Eric Fossum, while working at NASA's Jet Propulsion Laboratory (JPL), explained in public an improvement to the CMOS sensor: the integration of the pinned photodiode. A CMOS image sensor with a low-voltage-PPD technology was first fabricated in 1995 by a joint JPL and Kodak team that included Fossum along with P.P.K. Lee, R.C. Gee, R.M. Guidash and T.H. Lee. Since then, the PPD has been used in nearly all CMOS image sensors. The CMOS sensor with PPD technology was further advanced and refined by R.M. Guidash in 1997, K. Yonemoto and H. Sumi in 2000, and I. Inoue in 2003. This led to CMOS sensors achieve imaging performance on par with CCD sensors, and later exceeding CCD sensors. [20]

Photodiode array

A one-dimensional photodiode array chip with more than 200 diodes in the line across the center Photodiode array chip.jpg
A one-dimensional photodiode array chip with more than 200 diodes in the line across the center
A two-dimensional photodiode array of only 4 x 4 pixels occupies the left side of the first optical mouse sensor chip, c. 1982. Optical mouse chip detail.png
A two-dimensional photodiode array of only 4 × 4 pixels occupies the left side of the first optical mouse sensor chip, c. 1982.

A one-dimensional array of hundreds or thousands of photodiodes can be used as a position sensor, for example as part of an angle sensor. [23] A two-dimensional array is used in image sensors and optical mice.

In some applications, photodiode arrays allow for high-speed parallel readout, as opposed to integrating scanning electronics as in a charge-coupled device (CCD) or CMOS sensor. The optical mouse chip shown in the photo has parallel (not multiplexed) access to all 16 photodiodes in its 4 × 4 array.

Passive-pixel image sensor

The passive-pixel sensor (PPS) is a type of photodiode array. It was the precursor to the active-pixel sensor (APS). [20] A passive-pixel sensor consists of passive pixels which are read out without amplification, with each pixel consisting of a photodiode and a MOSFET switch. [24] In a photodiode array, pixels contain a p–n junction, integrated capacitor, and MOSFETs as selection transistors. A photodiode array was proposed by G. Weckler in 1968, predating the CCD. [25] This was the basis for the PPS. [20]

The noise of photodiode arrays is sometimes a limitation to performance. It was not possible to fabricate active pixel sensors with a practical pixel size in the 1970s, due to limited microlithography technology at the time. [25]

See also

Related Research Articles

<span class="mw-page-title-main">Charge-coupled device</span> Device for the movement of electrical charge

A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging.

<span class="mw-page-title-main">Diode</span> Two-terminal electronic component

A diode is a two-terminal electronic component that conducts current primarily in one direction. It has low resistance in one direction and high resistance in the other.

Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power. The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect. The photocurrent may be enhanced by internal gain caused by interaction among ions and photons under the influence of applied fields, such as occurs in an avalanche photodiode (APD).

A PIN diode is a diode with a wide, undoped intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor region. The p-type and n-type regions are typically heavily doped because they are used for ohmic contacts.

Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation.

<span class="mw-page-title-main">Optoelectronics</span> Branch of electronics involving optics

Optoelectronics is the study and application of electronic devices and systems that find, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation.

In electronics, an avalanche diode is a diode that is designed to experience avalanche breakdown at a specified reverse bias voltage. The junction of an avalanche diode is designed to prevent current concentration and resulting hot spots, so that the diode is undamaged by the breakdown. The avalanche breakdown is due to minority carriers accelerated enough to create ionization in the crystal lattice, producing more carriers, which in turn create more ionization. Because the avalanche breakdown is uniform across the whole junction, the breakdown voltage is nearly constant with changing current when compared to a non-avalanche diode.

An avalanche photodiode (APD) is a highly sensitive semiconductor photodiode detector that exploits the photoelectric effect to convert light into electricity. From a functional standpoint, they can be regarded as the semiconductor analog of photomultiplier tubes. The avalanche photodiode was invented by Japanese engineer Jun-ichi Nishizawa in 1952. However, study of avalanche breakdown, microplasma defects in silicon and germanium and the investigation of optical detection using p-n junctions predate this patent. Typical applications for APDs are laser rangefinders, long-range fiber-optic telecommunication, and quantum sensing for control algorithms. New applications include positron emission tomography and particle physics.

<span class="mw-page-title-main">Opto-isolator</span> Insulates two circuits from one another while allowing signals to pass through in one direction

An opto-isolator is an electronic component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and voltage transients with speeds up to 25 kV/μs.

<span class="mw-page-title-main">Video camera</span> Camera used for electronic motion picture acquisition

A video camera is an optical instrument that captures videos, as opposed to a movie camera, which records images on film. Video cameras were initially developed for the television industry but have since become widely used for a variety of other purposes.

A digital image is an image composed of picture elements, also known as pixels, each with finite, discrete quantities of numeric representation for its intensity or gray level that is an output from its two-dimensional functions fed as input by its spatial coordinates denoted with x, y on the x-axis and y-axis, respectively. Depending on whether the image resolution is fixed, it may be of vector or raster type. By itself, the term "digital image" usually refers to raster images or bitmapped images.

<span class="mw-page-title-main">Single-photon avalanche diode</span> Solid-state photodetector

A single-photon avalanche diode (SPAD), also called Geiger-mode avalanche photodiode is a solid-state photodetector within the same family as photodiodes and avalanche photodiodes (APDs), while also being fundamentally linked with basic diode behaviours. As with photodiodes and APDs, a SPAD is based around a semi-conductor p-n junction that can be illuminated with ionizing radiation such as gamma, x-rays, beta and alpha particles along with a wide portion of the electromagnetic spectrum from ultraviolet (UV) through the visible wavelengths and into the infrared (IR).

<span class="mw-page-title-main">Photodetector</span> Sensors of light or other electromagnetic energy

Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There are a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically use a p–n junction that converts photons into charge. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy.

<span class="mw-page-title-main">Electronic component</span> Discrete device in an electronic system

An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. A datasheet for an electronic component is a technical document that provides detailed information about the component's specifications, characteristics, and performance.

<span class="mw-page-title-main">Image sensor</span> Device that converts images into electronic signals

An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves into signals, small bursts of current that convey the information. The waves can be light or other electromagnetic radiation. Image sensors are used in electronic imaging devices of both analog and digital types, which include digital cameras, camera modules, camera phones, optical mouse devices, medical imaging equipment, night vision equipment such as thermal imaging devices, radar, sonar, and others. As technology changes, electronic and digital imaging tends to replace chemical and analog imaging.

<span class="mw-page-title-main">Active-pixel sensor</span> Image sensor, consisting of an integrated circuit

An active-pixel sensor (APS) is an image sensor, which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector and one or more active transistors. In a metal–oxide–semiconductor (MOS) active-pixel sensor, MOS field-effect transistors (MOSFETs) are used as amplifiers. There are different types of APS, including the early NMOS APS and the now much more common complementary MOS (CMOS) APS, also known as the CMOS sensor. CMOS sensors are used in digital camera technologies such as cell phone cameras, web cameras, most modern digital pocket cameras, most digital single-lens reflex cameras (DSLRs), mirrorless interchangeable-lens cameras (MILCs), and lensless imaging for cells.

A position sensitive device and/or position sensitive detector (PSD) is an optical position sensor (OPS) that can measure a position of a light spot in one or two-dimensions on a sensor surface.

Eric R. Fossum is an Emmy award-winning American engineer and professor, who co-developed some of the active pixel image sensor with intra-pixel charge transfer, with the help of other scientists from the NASA Jet Propulsion Laboratory. He is currently a professor at Thayer School of Engineering in Dartmouth College.

In physics and in electronic engineering, dark current is the relatively small electric current that flows through photosensitive devices such as a photomultiplier tube, photodiode, or charge-coupled device even when no photons enter the device; it consists of the charges generated in the detector when no outside radiation is entering the detector. It is referred to as reverse bias leakage current in non-optical devices and is present in all diodes. Physically, dark current is due to the random generation of electrons and holes within the depletion region of the device.

<span class="mw-page-title-main">James R. Biard</span> American electrical engineer and inventor (1931–2022)

James Robert Biard was an American electrical engineer and inventor who held 73 U.S. patents. Some of his more significant patents include the first infrared light-emitting diode (LED), the optical isolator, Schottky clamped logic circuits, silicon Metal Oxide Semiconductor Read Only Memory, a low bulk leakage current avalanche photodetector, and fiber-optic data links. In 1980, Biard became a member of the staff of Texas A&M University as an Adjunct Professor of Electrical Engineering. In 1991, he was elected as a member into the National Academy of Engineering for contributions to semiconductor light-emitting diodes and lasers, Schotky-clamped logic, and read-only memories.

References

PD-icon.svg This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22.

  1. Pearsall, Thomas (2010). Photonics Essentials, 2nd edition. McGraw-Hill. ISBN   978-0-07-162935-5. Archived from the original on 2021-08-17. Retrieved 2021-02-25.
  2. Tavernier, Filip and Steyaert, Michiel (2011) High-Speed Optical Receivers with Integrated Photodiode in Nanoscale CMOS. Springer. ISBN   1-4419-9924-8. Chapter 3 From Light to Electric Current – The Photodiode
  3. 1 2 Häberlin, Heinrich (2012). Photovoltaics: System Design and Practice. John Wiley & Sons. pp. SA3–PA11–14. ISBN   9781119978381 . Retrieved 19 April 2019.
  4. "Photodiode Application Notes – Excelitas – see note 4" (PDF). Archived from the original (PDF) on 2014-11-13. Retrieved 2014-11-13.
  5. Pearsall, Thomas; Pollack, Martin (1985). Compound Semiconductor Photodiodes, Semiconductors and Semimetals, Vol 22D. Elsevier. pp. 173–245. doi:10.1016/S0080-8784(08)62953-1.
  6. Riordan, Michael; Hoddeson, Lillian (1998). Crystal Fire: The Invention of the Transistor and the Birth of the Information Age. W. W. Norton & Company. ISBN   9780393318517.
  7. "The phototransistor". Bell Laboratories Record. May 1950. Archived from the original on 2015-07-04. Retrieved 2012-04-09.
  8. Pérez-Tomás, Amador; Lima, Anderson; Billon, Quentin; Shirley, Ian; Catalan, Gustau; Lira-Cantú, Mónica (2018). "A Solar Transistor and Photoferroelectric Memory". Advanced Functional Materials. 28 (17): 1707099. doi:10.1002/adfm.201707099. hdl: 10261/199048 . ISSN   1616-3028. S2CID   102819292.
  9. Held. G, Introduction to Light Emitting Diode Technology and Applications, CRC Press, (Worldwide, 2008). Ch. 5 p. 116. ISBN   1-4200-7662-0
  10. Yin, Zongyou; Li, Hai; Li, Hong; Jiang, Lin; Shi, Yumeng; Sun, Yinghui; Lu, Gang; Zhang, Qing; Chen, Xiaodong; Zhang, Hua (21 December 2011). "Single-Layer MoS Phototransistors". ACS Nano. 6 (1): 74–80. arXiv: 1310.8066 . doi:10.1021/nn2024557. PMID   22165908. S2CID   27038582.
  11. Shanfield, Z. et al (1988) Investigation of radiation effects on semiconductor devices and integrated circuits [ dead link ], DNA-TR-88-221
  12. Iniewski, Krzysztof (ed.) (2010), Radiation Effects in Semiconductors, CRC Press, ISBN   978-1-4398-2694-2
  13. Zeller, H.R. (1995). "Cosmic ray induced failures in high power semiconductor devices". Solid-State Electronics. 38 (12): 2041–2046. Bibcode:1995SSEle..38.2041Z. doi:10.1016/0038-1101(95)00082-5.
  14. May, T.C.; Woods, M.H. (1979). "Alpha-particle-induced soft errors in dynamic memories". IEEE Transactions on Electron Devices. 26 (1): 2–9. Bibcode:1979ITED...26....2M. doi:10.1109/T-ED.1979.19370. S2CID   43748644. Cited in Baumann, R. C. (2004). "Soft errors in commercial integrated circuits". International Journal of High Speed Electronics and Systems . 14 (2): 299–309. doi:10.1142/S0129156404002363. alpha particles emitted from the natural radioactive decay of uranium, thorium, and daughter isotopes present as impurities in packaging materials were found to be the dominant cause of [soft error rate] in [dynamic random-access memories].
  15. Erzberger, Arno (2016-06-21). "Halbleitertechnik Der LED fehlt der Doppelpfeil". Elektronik (in German). Archived from the original on 2017-02-14. Retrieved 2017-02-14.
  16. Brooker, Graham (2009) Introduction to Sensors for Ranging and Imaging, ScitTech Publishing. p. 87. ISBN   9781891121746
  17. E. Aguilar Pelaez et al., "LED power reduction trade-offs for ambulatory pulse oximetry," 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Lyon, 2007, pp. 2296–2299. doi: 10.1109/IEMBS.2007.4352784, URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4352784&isnumber=4352185
  18. Photodiode Technical Guide Archived 2007-01-04 at the Wayback Machine on Hamamatsu website
  19. Knoll, F.G. (2010). Radiation detection and measurement, 4th ed. Wiley, Hoboken, NJ. p. 298. ISBN   978-0-470-13148-0
  20. 1 2 3 4 5 6 7 8 Fossum, Eric R.; Hondongwa, D. B. (2014). "A Review of the Pinned Photodiode for CCD and CMOS Image Sensors". IEEE Journal of the Electron Devices Society. 2 (3): 33–43. doi: 10.1109/JEDS.2014.2306412 .
  21. U.S. Patent 4,484,210, which was a floating-surface type buried photodioe with the similar structure of the 1975 Philips invention. Solid-state imaging device having a reduced image lag
  22. Teranishi, Nobuzaku; Kohono, A.; Ishihara, Yasuo; Oda, E.; Arai, K. (December 1982). "No image lag photodiode structure in the interline CCD image sensor". 1982 International Electron Devices Meeting. pp. 324–327. doi:10.1109/IEDM.1982.190285. S2CID   44669969.
  23. Gao, Wei (2010). Precision Nanometrology: Sensors and Measuring Systems for Nanomanufacturing. Springer. pp. 15–16. ISBN   978-1-84996-253-7.
  24. Kozlowski, L. J.; Luo, J.; Kleinhans, W. E.; Liu, T. (14 September 1998). Pain, Bedabrata; Lomheim, Terrence S. (eds.). "Comparison of passive and active pixel schemes for CMOS visible imagers". Infrared Readout Electronics IV. International Society for Optics and Photonics. 3360: 101–110. Bibcode:1998SPIE.3360..101K. doi:10.1117/12.584474. S2CID   123351913.
  25. 1 2 Fossum, Eric R. (12 July 1993). Blouke, Morley M. (ed.). "Active pixel sensors: are CCDs dinosaurs?". SPIE Proceedings Vol. 1900: Charge-Coupled Devices and Solid State Optical Sensors III. Charge-Coupled Devices and Solid State Optical Sensors III. International Society for Optics and Photonics. 1900: 2–14. Bibcode:1993SPIE.1900....2F. CiteSeerX   10.1.1.408.6558 . doi:10.1117/12.148585. S2CID   10556755.