12% Efficiency CuIn(Se,S)2 Photovoltaic Device Prepared Using a Hydrazine Solution Process

• Published in: Chemistry of materials Vol. 22; no. 3; pp. 1010 - 1014
• Main Authors: Liu, Wei, Mitzi, David B, Yuan, Min, Kellock, Andrew J, Chey, S. Jay, Gunawan, Oki
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09-02-2010
• Subjects: Electronic Materials; Optical Materials (including Non-Linear Optic, Photonic, and Optoelectronic Materials); Precursor Routes to Materials (including Polymer-Derived Ceramics)
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm901950q

Thin-film CuIn(Se,S)2 (i.e., CIS) absorbers have been solution-deposited using a hydrazine-based approach that offers the potential to significantly lower the fabrication cost for CIS solar cells. In this method, metal chalcogenides are completely dissolved in hydrazine, forming a homogeneous precursor solution. Film deposition is demonstrated by spin-coating of the precursor solution onto various substrates, including Mo-coated glass and thermally oxidized silicon wafers. Using this approach, no postdeposition anneal in a toxic Se or S-containing environment is needed to obtain CIS films. Instead, only a simple heat-treatment in an inert atmosphere is required, resulting in CIS films with good crystallinity. Bandgap tuning can readily be achieved by varying the amount of S incorporated into the film. Complete CIS devices with glass/Mo/CIS/CdS/i-ZnO/ITO structure are fabricated using absorbers produced via this hydrazine-based approach. Air Mass 1.5G power conversion efficiencies of as high as 12.2% have been achieved, demonstrating that this new approach has great potential as a low-cost alternative for high-efficiency CIS solar cell production.