Co-evaporated Cu2ZnSnSe4 films and devices

• Published in: Solar energy materials and solar cells Vol. 101; no. June 2012; pp. 154 - 159
• Main Authors: Repins, Ingrid, Beall, Carolyn, Vora, Nirav, DeHart, Clay, Kuciauskas, Darius, Dippo, Pat, To, Bobby, Mann, Jonathan, Hsu, Wan-Ching, Goodrich, Alan, Noufi, Rommel
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2012; Elsevier
• Subjects: Applied sciences; Co-evaporation; CZTS; Direct energy conversion and energy accumulation; Earth-abundant; EFFICIENCY; ELECTRIC CONDUCTIVITY; Electrical engineering. Electrical power engineering; Electrical power engineering; ELECTRONS; Energy; Exact sciences and technology; Kesterite; keterite; MATERIALS SCIENCE; Natural energy; Photoelectric conversion; PHOTOLUMINESCENCE; Photovoltaic conversion; QUANTUM EFFICIENCY; Solar cell; SOLAR CELLS; Solar cells. Photoelectrochemical cells; SOLAR ENERGY; Thin film; THIN FILMS; Solar cell; CZTS; Kesterite; Co-evaporation; Thin film; Earth-abundant; Performance evaluation; Atmospheric condition; Voltage current curve; Cross-over phenomenon; Photoluminescence; Zinc selenides; Quantum yield; Photovoltaic cell; Copper selenides; Tin selenides; Series resistance; Codeposition; Vacuum deposition
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2012.01.008

The use of vacuum co-evaporation to produce Cu2ZnSnSe4 photovoltaic devices with 9.15% total-area efficiency is described. These new results suggest that the early success of the atmospheric techniques for kesterite photovoltaics may be related to the ease with which one can control film composition and volatile phases, rather than a fundamental benefit of atmospheric conditions for film properties. The co-evaporation growth recipe is documented, as is the motivation for various features of the recipe. Characteristics of the resulting kesterite films and devices are shown in scanning electron micrographs, including photoluminescence, current-voltage, and quantum efficiency. Current-voltage curves demonstrate low series resistance without the light-dark cross-over seen in many devices in the literature. Band gap indicated by quantum efficiency and photoluminescence is roughly consistent with that expected from first principles calculation. ► Co-evaporation was used to produce 9.15%-efficient Cu2ZnSnSe4 photovoltaic devices. ► Current-voltage curves show low series resistance without light-dark cross-over. ► Measured band gap is roughly consistent with first principles calculation.