Aqueous Solution-Phase Selenized CuIn(S,Se)2 Thin Film Solar Cells Annealed under Inert Atmosphere
journal contributionposted on 14.10.2015, 00:00 by Yunjung Oh, Wooseok Yang, Jimin Kim, Kyoohee Woo, Jooho Moon
A nonvacuum solution-based approach can potentially be used to realize low cost, roll-to-roll fabrication of chalcopyrite CuIn(S,Se)2 (CISSe) thin film solar cells. However, most solution-based fabrication methods involve highly toxic solvents and inevitably require sulfurization and/or postselenization with hazardous H2S/H2Se gases. Herein, we introduce novel aqueous-based Cu–In–S and Se inks that contain an amine additive for producing a high-quality absorber layer. CISSe films were fabricated by simple deposition of Cu–In–S ink and Se ink followed by annealing under an inert atmosphere. Compositional and phase analyses confirmed that our simple aqueous ink-based method facilitated in-site selenization of the CIS layer. In addition, we investigated the molecular structures of our aqueous inks to determine how crystalline chalcopyrite absorber layers developed without sulfurization and/or postselenization. CISSe thin film solar cells annealed at 550 °C exhibited an efficiency of 4.55% under AM 1.5 illumination. The low-cost, nonvacuum method to deposit chalcopyrite absorber layers described here allows for safe and simple processing of thin film solar cells.