SPLTRAK Abstract Submission
Bandgap Dependence of Near-Conduction Band State in (AgyCu1-y)(InxGa1-x)Se2 Solar Cells
Michael F Miller1, Alexandra M Bothwell2, Nicholas Valdes3,6, Stefan Paetel4, Rouin Farshchi5,6, Ana Kanevce4, William Shafarman3, Darius Kuciauskas2, Aaron R Arehart1
1Department of Electrical & Computer Engineering, The Ohio State University, Columbus, OH, United States
/2National Renewable Energy Laboratory, Golden, CO, United States
/3Department of Materials Science & Engineering, University of Delaware, Newark, DE, United States
/4Zentrum für Sonnenenergie-und Wasserstoff-Forschung (ZSW), Stuttgart, Germany
/5MiaSolé Hi-Tech Corp., Santa Clara, CA, United States
/6First Solar, Inc., Santa Clara, CA, United States

(Ag,Cu)(In,Ga)Se2-based solar cells have achieved high collection efficiencies, but defects still limit efficiencies well below the theoretical limit. The near-conduction band defect, typically observed at EV+0.98 eV, has been ubiquitous across (Ag,Cu)(In,Ga)Se2 samples from multiple vendors. The current work explores a wider range of composition and demonstrates the trap energy varies relative to the valence band but is approximately constant relative to the conduction band (~EC-0.13 eV). There is also no definitive dependence of the trap concentration on composition.