Thermal Characteristics of High-Efficiency Photovoltaic Converters of High-Power Laser Light

The influence exerted by the heat removal conditions on the extent of overheating of photovoltaic converters of high-power (>103 W/cm2) laser light has been studied. The temperature of the p–n junction of photovoltaic cells was measured by recording the instantaneous values of the open-circuit voltage generated by laser light. The effect of cooling in high-efficiency photovoltaic cells (efficiency = 55%) via removal of a substantial part of absorbed optical power by the photocurrent into the external load was demonstrated. It was shown that, at laser radiation power of 2.5 W, the overheating of a photocell with an area of 1.7 × 10–3 cm2 relative to the copper heatsink temperature is 48°C in the no-load conditions and 30°C in operation with the optimal load.