Year: 2019
Type: article
Abstract: Layered indium selenide (InSe) is a van der Waals solid that has emerged as a promising material for high-performance ultrathin solar cells. The optoelectronic parameters that are critical to photoconversion efficiencies, such as hot carrier lifetime and surface recombination velocity, are however largely unexplored in InSe. Here, these key photophysical properties of layered InSe are measured with femtosecond transient reflection spectroscopy. The hot carrier cooling process is found to occur through phonon scattering. The surface recombination velocity and ambipolar diffusion coefficient are extracted from fits to the pump energy-dependent transient reflection kinetics using a free carrier diffusion model. The extracted surface recombination velocity is approximately an order of magnitude larger than that for methylammonium lead-iodide perovskites, suggesting that surface recombination is a principal source of photocarrier loss in InSe. The extracted ambipolar diffusion coefficient is consistent with previously reported values of InSe carrier mobility.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Northwestern University, Ministerstvo Školství, Mládeže a Tělovýchovy, Grantová Agentura České Republiky, Office of Science, Materials Research Science and Engineering Center, Harvard University, Division of Materials Research, Basic Energy Sciences
Awards: G1169090945, G12500569, G1329306526, G1794054907, G3454132534, G4131035492, G4285583887, G4289625387, MRSEC: Center for Multifunctional Materials, G4912152698, G5218300437, ARGONNE-NORTHWESTERN SOLAR ENERGY RESEARCH (ANSER) CENTER -- EFRC, G7304483037, Layered transition metal dichalcogenides nanostructures for electrocatalysis, G801469781, G8172060556, ARGONNE-NORTHWESTERN SOLAR ENERGY RESEARCH (ANSER) CENTER -- EFRC, G8720576029
OpenAlex ID: W2909651220