A new scheme of near-field thermophotovoltaic devices is proposed by introducing the intermediate-band absorber. The two-step excitation via the intermediate band provides a large photogenerated current density and maintains a high voltage output for the thermal-electric conversion. Energy dissipation processes in devices are analyzed by using the detailed balance model. Results show that the powers and efficiencies of thermophotovoltaic devices with intermediate bands in appropriate positions are clearly larger than those of the conventional counterparts. Based on the optical properties observed in experiments, three types of absorber materials are compared, which indicates that InAs with low energy bandgap is more suitable as a high-temperature material for photon absorptions than GaSb and Si. Comparing the performance of our model with experiments, we show that the InAs based thermophotovoltaic device allows the enhancement of efficiency over a range of gap sizes. The proposed model may open a new field in the application of thermophotovoltaic devices.

中文翻译：

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具有 InAs、GaSb 和 Si 基吸收体的中带辅助近场热光伏器件

通过引入中带吸收体，提出了一种新的近场热光伏器件方案。通过中间带的两步激发提供了大的光生电流密度，并为热电转换保持了高电压输出。使用详细的平衡模型分析设备中的能量耗散过程。结果表明，在适当位置具有中间带的热光伏器件的功率和效率明显大于传统对应器件的功率和效率。根据实验中观察到的光学特性，比较了三种类型的吸收材料，这表明低能带隙的 InAs 比 GaSb 和 Si 更适合作为高温光子吸收材料。将我们模型的性能与实验进行比较，我们表明基于 InAs 的热光伏器件可以提高一系列间隙尺寸的效率。所提出的模型可能为热光伏器件的应用开辟一个新领域。