A tin-based perovskite solar cell is a special type of perovskite solar cell, where the lead is substituted by tin. It has a tin-based perovskite structure (ASnX3), where 'A' is a 1+ cation and 'X' is a monovalent halogen anion. The methylammonium tin triiodide (CH3NH3SnI3) has a band gap of 1.2–1.3 eV, while formamidinium tin triiodide has a band gap of 1.4 eV.
Tin-based perovskite solar cells are still in the research phase and there are relatively few publications about them, compared to their counterpart, lead-based perovskite solar cells. This is mainly due to the instability of the 2+ oxidation state of tin (Sn2+) in methylammonium tin iodide (CH3NH3SnI3), which can be easily oxidized to the more stable Sn4+,leading to a process called self doping, where the Sn4+ acts as a p-dopant leading to the reduction in the solar cell efficiency.
The maximum solar cell efficiency reported is 6.4% for methylammonium tin iodide (CH3NH3SnI3),5.73% for CH3NH3SnIBr2, 2.02% for CsSnI3. and above 9% for formamidinium tin triiodide (CH(NH2)2SnI3).
The main advantages of tin-based perovskite solar cells are that they are lead-free and that can help to further tune the band-gap of the active layer. There are environmental concerns with using lead-based perovskite solar cells in large-scale applications;one such concern is that since the material is soluble in water, and lead is highly toxic, any contamination from damaged solar cells could cause major health and environmental problems.
In spite of an earlier reported low efficiency, formamidinium tin triiodide may hold promise because, applied as a thin film, it appears to have the potential to exceed the Shockley–Queisser limit by allowing hot-electron capture, which could considerably raise the efficiency.
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius. However, it readily sublimes with gentle heat, resulting in a widespread misconception even taught in some science textbooks that it does not melt at standard pressure. The element was discovered by the French chemist Bernard Courtois in 1811, and was named two years later by Joseph Louis Gay-Lussac, after the Greek ἰώδης "violet-coloured".
A perovskite is any material with a crystal structure similar to the mineral called perovskite, which consists of calcium titanium oxide (CaTiO3). The mineral was first discovered in the Ural mountains of Russia by Gustav Rose in 1839 and named after Russian mineralogist L. A. Perovski (1792–1856). The general chemical formula for perovskite compounds is ABX3, where 'A' and 'B' are two cations, often of very different sizes, and X is an anion (frequently oxide) that bonds to both cations. The 'A' atoms are generally larger than the 'B' atoms. The ideal cubic structure has the B cation in 6-fold coordination, surrounded by an octahedron of anions, and the A cation in 12-fold cuboctahedral coordination.
A scintillator is a material that exhibits scintillation, the property of luminescence, when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate. Sometimes, the excited state is metastable, so the relaxation back down from the excited state to lower states is delayed. The process then corresponds to one of two phenomena: delayed fluorescence or phosphorescence. The correspondence depends on the type of transition and hence the wavelength of the emitted optical photon.
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially utilized for electricity generation and as photosensors.
Lead(II) iodide or lead iodide is a salt with the formula PbI
2. At room temperature, it is a bright yellow odorless crystalline solid, that becomes orange and red when heated. It was formerly called plumbous iodide.
Amidines are organic compounds with the functional group RC(NR)NR2, where the R groups can be the same or different. They are the imine derivatives of amides (RC(O)NR2). The simplest amidine is formamidine, HC(=NH)NH2.
A dye-sensitized solar cell is a low-cost solar cell belonging to the group of thin film solar cells. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a photoelectrochemical system. The modern version of a dye solar cell, also known as the Grätzel cell, was originally co-invented in 1988 by Brian O'Regan and Michael Grätzel at UC Berkeley and this work was later developed by the aforementioned scientists at the École Polytechnique Fédérale de Lausanne (EPFL) until the publication of the first high efficiency DSSC in 1991. Michael Grätzel has been awarded the 2010 Millennium Technology Prize for this invention.
Copper(I) iodide is the inorganic compound with the formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding.
Piezochromism describes the tendency of certain materials to change color with the application of pressure. This effect is closely related to the electronic band gap change, which can be found in plastics, semiconductors and hydrocarbons.
Building-integrated photovoltaics (BIPV) are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof, skylights, or facades. They are increasingly being incorporated into the construction of new buildings as a principal or ancillary source of electrical power, although existing buildings may be retrofitted with similar technology. The advantage of integrated photovoltaics over more common non-integrated systems is that the initial cost can be offset by reducing the amount spent on building materials and labor that would normally be used to construct the part of the building that the BIPV modules replace. These advantages make BIPV one of the fastest growing segments of the photovoltaic industry.
Tin(II) sulfide is a chemical compound of tin and sulfur. The chemical formula is SnS. Its natural occurrence concerns herzenbergite (α-SnS), a rare mineral. At elevated temperatures above 905 K, SnS undergoes a second order phase transition to β-SnS (space group: Cmcm, No. 63). in recent years, it has become evident that a new polymorph of SnS exists based upon the cubic crystal system, known as π-SnS (space group: P213, No. 198).
A perovskite solar cell (PSC) is a type of solar cell which includes a perovskite-structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer. Perovskite materials, such as methylammonium lead halides and all-inorganic cesium lead halide, are cheap to produce and simple to manufacture.
Methylammonium halides are organic halides with a formula of CH3NH3X, where X is Cl, Br or I. Generally they are white or light colored powders. They are used primarily to prepare light absorbing semiconductors for perovskite solar cells.
Methylammonium lead halides (MALHs) are solid compounds with perovskite structure and a chemical formula of CH3NH3PbX3, where X = I, Br or Cl. They have potential applications in solar cells, lasers, light-emitting diodes, photodetectors, radiation detectors, scintillator, magneto-optical data storage and hydrogen production.
Mercouri Kanatzidis is a Charles E. and Emma H. Morrison Professor of Chemistry and Professor of Materials Science and Engineering at Northwestern University and Senior Scientist at Argonne National Laboratory.
Robert P. H. Chang is an American materials scientist who served as the president of the Materials Research Society (1989) and as a general secretary and president of the International Union of Materials Research Societies (IUMRS). Currently Chang heads the Materials Research Institute at Northwestern University. He is a member of advisory boards of the National Institute for Materials Science and of the journal Science and Technology of Advanced Materials.
Maksym V. Kovalenko is a full professor of inorganic chemistry and the head of the Functional Inorganic Materials group at ETH Zurich. A part of the research activities of the group are conducted at Empa (Dübendorf). He is working in the fields of solid-state chemistry, quantum dots and other nanomaterials, surface chemistry, self-assembly, optical spectroscopy, optoelectronics and energy storage.
Perovskite nanocrystals are a class of semiconductor nanocrystals, which exhibit unique characteristics that separate them from traditional quantum dots. Perovskite nanocrystals have an ABX3 composition where A = cesium, methylammonium (MA), or formamidinium (FA); B = lead or tin; and X = chloride, bromide, or iodide.
Hemamala Indivari Karunadasa is an Assistant Professor of Chemistry at Stanford University. She works on hybrid organic – inorganic materials, such as perovskites, for clean energy and large area lighting.
Light soaking refers to the change in power output of solar cells which can be measured after illumination. This can either be an increase or decrease, depending on the type of solar cell. The cause of this effect and the consequences on efficiency varies per type of solar cell. Light soaking can generally cause either metastable electrical or structural effects. Electrical effects can vary the efficiency depending on illumination, electrical bias and temperature, where structural effects actually changes the structure of the material and performance is often permanently altered.