Non-contact thermoelectric integration for high-concentration photovoltaic thermal management and energy recovery

Concentrated photovoltaic (CPV) technology offers significant advantages in achieving high power density; however, waste heat accumulation under high concentration can reduce cell efficiency and compromise system stability. This study proposes a non-contact concentrated photovoltaic-thermoelectric generator (CPV-TEG) hybrid system, in which the thermoelectric generator (TEG) module is laterally displaced from the CPV receiver and positioned adjacent to the high-temperature focal-plane region. The TEG harvests residual thermal energy generated under concentrated solar illumination while remaining thermally independent of the CPV heat dissipation pathway. This architecture achieves thermal decoupling between thermoelectric energy harvesting and photovoltaic thermal management. The system integrates a GaInP/InGaAs/Ge triple-junction solar cell incorporating a high-current–density AlGaAs/GaInP heterojunction tunnel junction. The tunnel junction exhibits a peak current density of 14.45 A/cm 2 , sufficient to support large-current carrier transport under 1000-sun concentration, while the fabricated triple-junction cell achieves a photovoltaic conversion efficiency of 40.32 %. Furthermore, a CPV array consisting of 30 cells connected in a 6-series/5-parallel configuration was developed and integrated with a secondary concentrating prism and an automatic solar-tracking system. Experimental results demonstrate that, compared with conventional stacked CPV-TEG architectures, the proposed non-contact configuration removes the TEG module from the CPV’s primary heat dissipation path, thereby eliminating the additional thermal resistance introduced by the TEG. This reduces the operating temperature of the CPV module by 7.1 °C and provides an additional power output of approximately 1.15 W without reducing photovoltaic output. The proposed approach offers a new pathway for synergistic optimization of photovoltaic power generation and thermal-energy utilization in high-concentration solar energy systems.