Search

Your search keyword '"Snaith, Henry J."' showing total 208 results
Start Over Author "Snaith, Henry J." Publisher american chemical society
208 results on '"Snaith, Henry J."'

14. Isotype heterojunction solar cells using n-type Sb₂Se₃ thin films

Author

Hobson, Theodore DC, Phillips, Laurie J, Hutter, Oliver S, Shiel, Huw, Swallow, Jack EN, Savory, Christopher N, Nayak, Pabitra K, Mariotti, Silvia, Das, Bhaskar, Bowen, Leon, Jones, Leanne AH, Featherstone, Thomas J, Smiles, Matthew J, Farnworth, Mark A, Zoppi, Guillaume, Thakur, Pardeep K, Lee, Tien-Lin, Snaith, Henry J, Leighton, Chris, Scanlon, David O, Dhanak, Vinod R, Durose, Ken, Veal, Tim D, and Major, Jonathan D

Abstract

The carrier-type of the emerging photovoltaic Sb2Se3 was evaluated for both thin films and bulk crystals via a range of complementary techniques. X-ray photoelectron spectroscopy (XPS), hot probe, Hall effect, and surface photovoltage spectroscopy showed films and crystals synthesized from the Sb2Se3 granulate material to be n-type with chlorine identified as an unintentional n-type dopant via secondary ion mass spectrometry analysis. The validity of chlorine as a dopant was confirmed by the synthesis of intrinsic crystals from metallic precursors and subsequent deliberate n-type doping by the addition of MgCl2. Chlorine was also shown to be a substitutional n-type shallow dopant by density functional theory calculations. TiO2/Sb2Se3 n–n isotype heterojunction solar cells with 7.3% efficiency are subsequently demonstrated, with band alignment analyzed via XPS.

Published
2020

15. Thermally Stable Passivation toward High Efficiency Inverted Perovskite Solar Cells

Author

Oliver, Robert D.J., Lin, Yen Hung, Horn, Alexander J., Xia, Chelsea Q., Warby, Jonathan H., Johnston, Michael B., Ramadan, Alexandra J., Snaith, Henry J., Oliver, Robert D.J., Lin, Yen Hung, Horn, Alexander J., Xia, Chelsea Q., Warby, Jonathan H., Johnston, Michael B., Ramadan, Alexandra J., and Snaith, Henry J.

Abstract

Although metal halide perovskite photovoltaics have shown an unprecedented rise in power conversion efficiency (PCE), they remain far from their theoretical PCE limit. Among the highest efficiencies to date are delivered when polycrystalline films are enhanced via "molecular passivation", but this can introduce new instabilities, in particular under severe accelerated aging conditions (e.g., at 85 °C in the dark or under full spectrum simulated sunlight). Here, we utilize a benzylammonium bromide passivation treatment to improve device performance, achieving the champion stabilized power output (SPO) of 19.5 % in a p-i-n device architecture. We correlate the improved device performance with a significant increase in charge carrier diffusion lengths, mobilities, and lifetimes. Furthermore, treated devices maintain an increased performance during 120 h combined stressing under simulated full spectrum sunlight at 85 °C, indicating that enhancement from this passivation treatment is sustained under harsh accelerated aging conditions. This is a crucial step toward real-world operation-relevant passivation treatments. © 2020 American Chemical Society. All rights reserved.

Published
2020

35. Charge-Carrier Dynamics in 2D Hybrid Metal–Halide Perovskites

Author

Milot, Rebecca L., Sutton, Rebecca J., Eperon, Giles E., Haghighirad, Amir Abbas, Martinez Hardigree, Josue, Miranda, Laura, Snaith, Henry J., Johnston, Michael B., and Herz, Laura M.

Abstract

Hybrid metal–halide perovskites are promising new materials for use in solar cells; however, their chemical stability in the presence of moisture remains a significant drawback. Quasi two-dimensional (2D) perovskites that incorporate hydrophobic organic interlayers offer improved resistance to degradation by moisture, currently still at the cost of overall cell efficiency. To elucidate the factors affecting the optoelectronic properties of these materials, we have investigated the charge transport properties and crystallographic orientation of mixed methylammonium (MA)–phenylethylammonium (PEA) lead iodide thin films as a function of the MA-to-PEA ratio and, thus, the thickness of the “encapsulated” MA lead–halide layers. We find that monomolecular charge-carrier recombination rates first decrease with increasing PEA fraction, most likely as a result of trap passivation, but then increase significantly as excitonic effects begin to dominate for thin confined layers. Bimolecular and Auger recombination rate constants are found to be sensitive to changes in electronic confinement, which alters the density of states for electronic transitions. We demonstrate that effective charge-carrier mobilities remain remarkably high (near 10 cm2V−1s−1) for intermediate PEA content and are enhanced for preferential orientation of the conducting lead iodide layers along the probing electric field. The trade-off between trap reduction, electronic confinement, and layer orientation leads to calculated charge-carrier diffusion lengths reaching a maximum of 2.5 μm for intermediate PEA content (50%).

Published
2016

36. Electron transport and recombination in dye-sensitized mesoporous Ti[O.sub.2] probed by photoinduced charge-conductivity modulation spectroscopy with Monte Carlo modeling

Author

Petrozza, Annamaria, Groves, Chris, and Snaith, Henry J.

Subjects
Electron transport -- Analysis, Absorption of light -- Measurement, Monte Carlo method -- Usage, Organic dyes -- Chemical properties, Organic dyes -- Electric properties, Chemistry
Abstract

A new method is described for measuring the electron transport and recombination in dye-sensitized mesoporous materials in which the charge density is detected directly by quasi-continuous wave (cw) optical absorption measurements while simultaneously electronically measuring the conductivity through in-plane devices. The results have shown that at room temperature the recombination is weakly influenced by the charge transport and is mainly affected by the recombination reaction and the cation density.

Published
2008

37. Enhancing the Charge Extraction and Stability of Perovskite Solar Cells Using Strontium Titanate (SrTiO3) Electron Transport Layer.

Author

Neophytou, Marios, De Bastiani, Michele, Gasparini, Nicola, Aydin, Erkan, Ugur, Esma, Seitkhan, Akmaral, Moruzzi, Floriana, Choaie, Yasmin, Ramadan, Alexandra J., Troughton, Joel R., Hallani, Rawad, Savva, Achilleas, Tsetseris, Leonidas, Inal, Sahika, Baran, Derya, Laquai, Frédéric, Anthopoulos, Thomas D., Snaith, Henry J., De Wolf, Stefaan, and McCulloch, Iain

Published
2019
Full Text
View/download PDF

46. Highly efficient perovskite solar cells with tunable structural color

Author

Zhang, Wei, Anaya Martín, Miguel, Lozano Barbero, Gabriel Sebastián, Calvo Roggiani, Mauricio, Johnston, Michael B., Míguez García, Hernán Ruy, Snaith, Henry J., Zhang, Wei, Anaya Martín, Miguel, Lozano Barbero, Gabriel Sebastián, Calvo Roggiani, Mauricio, Johnston, Michael B., Míguez García, Hernán Ruy, and Snaith, Henry J.

Abstract

The performance of perovskite solar cells has been progressing over the past few years and efficiency is likely to continue to increase. However, a negative aspect for the integration of perovskite solar cells in the built environment is that the color gamut available in these materials is very limited and does not cover the green-to-blue region of the visible spectrum, which has been a big selling point for organic photovoltaics. Here, we integrate a porous photonic crystal (PC) scaffold within the photoactive layer of an opaque perovskite solar cell following a bottom-up approach employing inexpensive and scalable liquid processing techniques. The photovoltaic devices presented herein show high efficiency with tunable color across the visible spectrum. This now imbues the perovskite solar cells with highly desirable properties for cladding in the built environment and encourages design of sustainable colorful buildings and iridescent electric vehicles as future power generation sources.

Published
2015

47. Optical Description of Mesostructured Organic¿Inorganic Halide Perovskite Solar Cells

Author

Anaya, Miguel, Lozano, Gabriel, Calvo, Mauricio E., Zhang, Wei, Johnston, Michael B., Snaith, Henry J., Míguez, Hernán, Anaya, Miguel, Lozano, Gabriel, Calvo, Mauricio E., Zhang, Wei, Johnston, Michael B., Snaith, Henry J., and Míguez, Hernán

Abstract

Herein we describe both theoretically and experimentally the optical response of solution-processed organic¿inorganic halide perovskite solar cells based on mesostructured scaffolds. We develop a rigorous theoretical model using a method based on the propagation of waves in layered media, which allows visualizing the way in which light is spatially distributed across the device and serves to quantify the fraction of light absorbed by each medium comprising the cell. The discrimination between productive and parasitic absorption yields an accurate determination of the internal quantum efficiency. State-of-the-art devices integrating mesoporous scaffolds infiltrated with perovskite are manufactured and characterized to support the calculations. This combined experimental and theoretical analysis provides a rational understanding of the optical behavior of perovskite cells and can be beneficial for the judicious design of devices with improved performance. Notably, our model justifies the presence of a solid perovskite capping layer in all of the highest efficiency perovskite solar cells based on thinner mesoporous scaffolds.

Published
2015

48. Optical Description of Mesostructured Organic−Inorganic Halide Perovskite Solar Cells

Author

European Commission, Anaya, Miguel, Lozano, Gabriel, Calvo, Mauricio E., Zhang, Wei, Johnston, Michael B., Snaith, Henry J., Míguez, Hernán, European Commission, Anaya, Miguel, Lozano, Gabriel, Calvo, Mauricio E., Zhang, Wei, Johnston, Michael B., Snaith, Henry J., and Míguez, Hernán

Abstract

Herein we describe both theoretically and experimentally the optical response of solution-processed organic−inorganic halide perovskite solar cells based on mesostructured scaffolds. We develop a rigorous theoretical model using a method based on the propagation of waves in layered media, which allows visualizing the way in which light is spatially distributed across the device and serves to quantify the fraction of light absorbed by each medium comprising the cell. The discrimination between productive and parasitic absorption yields an accurate determination of the internal quantum efficiency. State-of-the-art devices integrating mesoporous scaffolds infiltrated with perovskite are manufactured and characterized to support the calculations. This combined experimental and theoretical analysis provides a rational understanding of the optical behavior of perovskite cells and can be beneficial for the judicious design of devices with improved performance. Notably, our model justifies the presence of a solid perovskite capping layer in all of the highest efficiency perovskite solar cells based on thinner mesoporous scaffolds

Published
2015

Catalog

Books, media, physical & digital resources
See catalog results