Thermally co-evaporated ternary chalcogenide AgBiS2 thin films for photovoltaic applications: new route for AgBiS2 synthesis and phase investigation

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 27; pp. 16831 - 16838
• Main Authors: Choi, Minho, Kim, Suwhan, Lee, Minwoo, Jae Sung Yun, Karade, Vijay C, Lim, Jongchul, Yang, JungYup, Park, Jongsung
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 09.07.2024
• Subjects: Absorptivity; Crystallinity; Energy conversion efficiency; Evaporation; Fabrication; Open circuit voltage; Photovoltaic cells; Photovoltaics; Solar cells; Thin films
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta01661k

AgBiS2 films have recently garnered considerable interest for photovoltaic applications because of their optimal bandgap and high absorption coefficient. Nevertheless, their fabrication has been confined to solution-based processes, which limits their scalability and makes the production of large-area devices challenging. This paper presents the successful fabrication of phase-pure AgBiS2 thin films using a thermal co-evaporation technique and their application in thin-film solar cells. The fabrication process utilized a compositional engineering approach that involved thermal co-evaporation of the precursor powders of Ag2S and Bi2S3. Initial optimization experiments were conducted to determine the optimal Ag/Bi composition and crystallinity. It was found that thin films with a 1 : 1 Ag : Bi ratio post-annealed at 200 °C for 10 minutes exhibited the most favorable microstructure with high crystallinity. Consequently, a notable power conversion efficiency of 1.52% and an open circuit voltage of 346 mV were achieved. These findings pave the way for the production of AgBiS2 thin-film solar cells using the thermal co-evaporation method for both research settings and commercial applications.