To better suit the bandgap of solar cell, we proposed a novel theoretical model of solar thermophotovoltaic system, which consists of a concentrator, a surface-textured absorber, an emitter, a photovoltaic cell, and a downconversion layer. Two configurations of rear and front down converters are proposed to enhance the performance of the solar thermophotovoltaic system. The corresponding expressions of particle and heat fluxes are derived. Based on balance equations of particle and energy, the temperatures of emitter and solar cell, and the voltages of down converter are determined. In addition, the influences of solar concentration ratio, geometrical factor, and refractive indexes of emitter and solar cell are considered. Moreover, the operating voltage of solar cell, the areas of emitter and solar cell, and the bandgap of solar cell are optimized at the maximum efficiency condition. The results show that the existence of down converter can efficiently enhance the performance of the solar thermophotovoltaic system, and the proposed configurations can provide theoretical guidance for efficient solar energy harvesting.

中文翻译：

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通过高能光子的下转换提高太阳能热光伏电池的效率

为了更好地适应太阳能电池的带隙，我们提出了一种新型的太阳能热光伏系统理论模型，该模型由聚光器、表面纹理吸收器、发射器、光伏电池和下转换层组成。提出了后下变频器和前下变频器的两种配置，以提高太阳能热光伏系统的性能。推导出粒子流和热流的相应表达式。根据粒子和能量的平衡方程，确定了发射极和太阳能电池的温度，以及下变频器的电压。此外，还考虑了太阳能集中比、几何因素以及发射极和太阳能电池的折射率的影响。此外，太阳能电池的工作电压，发射极和太阳能电池的面积，并且在最大效率条件下优化太阳能电池的带隙。结果表明，下变频器的存在可以有效提高太阳能热光伏系统的性能，所提出的配置可以为高效的太阳能收集提供理论指导。