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

Journal Article · Mon Jun 23 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4884817· OSTI ID:22303878

Guglietta, Glenn W.; Baxter, Jason B. ^[1]; Choudhury, Kaushik Roy; Caspar, Jonathan V. ^[2]

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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)

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.

• OSTI ID: 22303878
• Journal Information: Applied Physics Letters, Vol. 104, Issue 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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