High-Efficiency InP/InGaAs Thermophotovoltaics Enabled by a Double-Heterojunction Design

To enable efficient waste heat recovery, this study proposes a thermophotovoltaic (TPV) cell design based on an InP/InGaAs heterojunction, optimized for high energy conversion efficiency and simplified fabrication. The cell features InGaAs as the absorber and InP as the emitter, both grown on an InP substrate. Using the SCAPS-1D simulation platform, we conducted a comprehensive analysis of the device’s band structure and theoretical performance. Key parameters, such as layer thickness and doping concentrations, were systematically optimized to enhance carrier mobility, lifetime, and diffusion length. Under 1400 K blackbody thermal irradiation, the optimized cell exhibits robust photovoltaic performance: a short-circuit current density (Jsc) of 2678.86 mA/cm2, an open-circuit voltage (Voc) of 0.423 V, and a fill factor (FF) of 78.03%, yielding an in-band power conversion efficiency (ηin-band) of 24.58%. These results highlight the cell’s strong response to infrared photons and demonstrate the advantages of the structural design, which provide high thermal stability and promote efficient carrier collection at elevated temperatures. This work not only advances theoretical understanding but also introduces a commercially viable pathway for high-efficiency TPV device design to reduce fabrication complexity and cost.