热光伏能量转换器件的热力学极限与优化性能预测

受不可逆损失的影响,热光伏能量转换器件在高品位热能回收与利用方面受到限制.本文揭示不可逆损失来源,提供热光伏能量转换器件性能提升方案.利用半导体物理和普朗克热辐射理论,确定热光伏能量转换器件在理想条件下的最大效率.进而考虑Auger与Shockley-Reed-Hall非辐射复合和不可逆传热损失对光伏电池的电学、光学和热学特性的影响,预测热光伏器件优化性能.确定功率密度、效率和光子截止能量的优化区间.结果表明:相比于理想热光伏器件,非理想热光伏器件的开路电压、短路电流密度和效率有所降低;优化热光伏电池电压、光子截止能量和热源温度,可提升器件的功率密度和效率.通过对比发现理论与实验结果较一致,所得结果可为实际热光伏能量转换器件的研制提供理论指导.

Thermodynamic limit and optimal performance prediction of thermophotovoltaic energy conversion devices

The application of thermophotovoltaic energy conversion device to recovery and utilization of high-grade thermal energy are limited by its irreversible loss. In this work, we reveal the source of irreversible loss and provide a strategy for improving the performance of thermophotovoltaic energy conversion device. The maximum efficiency of thermophotovoltaic energy conversion device under ideal condition is determined by using the theory of semiconductor physics and Planck thermal radiation. Moreover, the effects of non-radiative recombination and irreversible heat transfer loss on the electrical, optical, and thermal characteristics of thermophotovoltaic device are considered to predict the optimal performance of thermophotovoltaic device. The optimal region of power density, efficiency, and photon cut-off energy are determined. The obtained results show that the open-circuit voltage, short-circuit current density and efficiency of non-ideal device are lower than those of ideal device. The voltage output and photon cut-off energy of thermophotovoltaic device and heat source temperature can be optimized to improve the power density and efficiency of the device. It is found that the theoretical results are in good agreement with the experimental results, which can provide some guidances fordeveloping the practical thermophotovoltaic devices.