Bandgap Dependence of Near-Conduction Band State in $(\text{Ag}_{\mathrm{y}}\text{Cu}_{1-\mathrm{y}})(\text{In}_{\mathrm{X}}\text{Ga}_{1-\mathrm{x}})\text{Se}_{2}$ Solar Cells

(Ag, CU)
$(\mathbf{In}, \mathbf{Ga})\mathbf{Se}_{\boldsymbol{2}}$
-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
$\mathbf{E}_{\mathbf{V}}\boldsymbol{+0.98}$
eV, has been ubiquitous across
$(\mathbf{Ag},\mathbf{Cu}) (\mathbf{In}, \mathbf{Ga})\mathbf{Se}_{\boldsymbol{2}}$
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.