Atomic Layer Deposited Gallium Oxide Buffer Layer Enables 1.2 V Open‐Circuit Voltage in Cuprous Oxide Solar Cells

Abstract

The power conversion efficiency of solar cells based on copper (I) oxide (Cu2 O) is enhanced by atomic layer deposition of a thin gallium oxide (Ga2 O3 ) layer. By improving band-alignment and passivating interface defects, the device exhibits an open-circuit voltage of 1.20 V and an efficiency of 3.97%, showing potential of over 7% efficiency.