Large-area III-nitride double-heterojunction solar cells with record-high in-content InGaN absorbing layers

This work investigates the MBE growth, material characterization, and performance testing of large-area InGaN/GaN double-heterojunction solar cells. Structures with varying thicknesses and compositions of the InGaN absorbing layer are studied. The N-rich MBE growth at low temperatures enables the growth of thick 10% and 20% InGaN films with minimal relaxation. While current leakage is an issue for these large-area devices as detected by I-V and concentration effect measurements, the double-heterojunction cell with a record-high In content of 22% shows a promising photovoltaic response.