Performance Enhancement of InGaN Laser Photovoltaic Cell With AlGaN Strain Compensation Layer Irradiated by 450 nm Laser

A high-efficiency indium gallium nitride (InGaN) laser photovoltaic cell (LPVC) was demonstrated to achieve a photoelectric conversion efficiency (η) of 23.09% by incorporating an AlGaN strain compensation layer (SCL) grown on a (0001)-oriented patterned sapphire substrate (PSS). The photoluminescence spectra confirm that the peak splitting is reduced after the insertion of AlGaN SCL, indicating a more uniform distribution of In. In addition, the full width at half maximum of the sample is narrowed, indicating that the crystal quality is improved after the insertion of AlGaN SCL. The X-ray diffraction analysis reveals the effective modulation of strain relaxation in InGaN materials by the AlGaN SCL, enhancing steepness of the interface between the well and the barrier in the active region compared with materials without the AlGaN SCL. Furthermore, Raman analysis shows an additional release of GaN compressive stress in InGaN materials, providing full validation for the stress regulation model from introducing the AlGaN SCL. Finally, introducing material parameters into Silvaco software resulted in simulation and experimental errors of less than 2%, the critical role of SCL in efficiency improvement is validated. Valuable insights on optimizing device design for high-efficiency InGaN LPVCs are provided.