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Title: Employing time-resolved terahertz spectroscopy to analyze carrier dynamics in thin-film Cu{sub 2}ZnSn(S,Se){sub 4} absorber layers

We report the application of time-resolved terahertz spectroscopy (TRTS) to measure photoexcited carrier lifetimes and mobility, and to determine recombination mechanisms in Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) thin films fabricated from nanocrystal inks. Ultrafast time resolution permits tracking the evolution of carrier density to determine recombination rates and mechanisms. The carrier generation profile was manipulated by varying the photoexcitation wavelength and fluence to distinguish between surface, Shockley-Read-Hall (SRH), radiative, and Auger recombination mechanisms and determine rate constants. Surface and SRH recombination are the dominant mechanisms for the air/CZTSSe/SiO{sub 2}/Si film stack. Diffusion to, and then recombination at, the air-CZTSSe interface occurred on the order of 100 picoseconds, while SRH recombination lifetimes were 1–2 nanoseconds. TRTS measurements can provide information that is complementary to conventional time-resolved photoluminescence measurements and can direct the design of efficient thin film photovoltaics.
Authors:
;  [1] ; ;  [2]
  1. Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)
  2. DuPont Central Research and Development, Experimental Station, Wilmington, Delaware 19880 (United States)
Publication Date:
OSTI Identifier:
22303878
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AUGER EFFECT; CARRIER DENSITY; CARRIER LIFETIME; CARRIER MOBILITY; COPPER COMPOUNDS; DIFFUSION; INTERFACES; LAYERS; NANOSTRUCTURES; PHOTOLUMINESCENCE; PHOTOVOLTAIC EFFECT; RECOMBINATION; SELENIUM COMPOUNDS; SPECTROSCOPY; SULFUR COMPOUNDS; SURFACES; THIN FILMS; TIME RESOLUTION; TIN COMPOUNDS; ZINC COMPOUNDS