Surface Texture-Induced Enhancement of Optical and Photoelectrochemical Activity of Cu^sub 2^ZnSnS^sub 4^ Photocathodes

• Published in: Journal of electronic materials Vol. 46; no. 8; p. 5308
• Main Authors: Sarswat, Prashant K, Deka, Nipon, Jagan Mohan Rao, S, Free, Michael L, Kumar, Gagan
• Format: Journal Article
• Language: English
• Published: Warrendale Springer Nature B.V 01-08-2017
• Subjects: Anodizing; Catalysis; Catalytic activity; Charge transfer; Computer simulation; Electrolytes; Etching; Finite difference method; Finite difference time domain method; Flakes; Flux; Ion flux; Materials research; Materials selection; Photocatalysis; Photocathodes; Power loss; Solvents; Stoichiometry; Surface area; Surface chemistry; Surface properties; Texturing; Thin films; Time domain analysis; Time measurement; Zinc sulfide
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-017-5531-8

The objective of this work is to understand and improve the photocatalytic activity of Cu2ZnSnS4 (CZTS) through postgrowth modification techniques to create surface textures. This objective can be achieved using a combination of solvents, etching agents, and anodization techniques. One of the most effective surface treatments for enhancing the surface properties of photovoltaic materials is formation of nanoscale flakes, although other surface modifications were also evaluated. The superior performance of textured films can be attributed to enhanced surface area of absorber material exposed to electrolyte, ZnS deficiency, and high catalytic activity due to reduced charge-transfer resistance. Fine-tuning of ion flux and electrolyte stoichiometry can be used to create a controlled growth algorithm for CZTS thin films. The resulting information can be utilized to optimize film properties. The utility of nanostructured or engineered surfaces was evaluated using photoelectrochemical measurements. Finite-difference time-domain (FDTD)-assisted simulations were conducted for selected texturing, revealing enhanced surface area of absorbing medium that ultimately resulted in greater power loss of light in the medium.