To realize a high-performance solid-state photon-enhanced thermionic emission (SPETE) solar energy converter, in this study, a graded bandgap window layer is therefore adopted, throughout which the bandgap gradation is generated via the variation of Al composition in the layer in the SPETE converter with a GaAs absorber. Based on one-dimension steady-state equation, an analytical model is formed in analyzing performance of the proposed device in our study. Theoretical simulation results indicate that not only are the losses of contact surface recombination being decreased via the bandgap-gradation-induced build-in electric field of the window layer, but also the photon-generated electrons are effectively collected, thereby improving the conversion efficiency. Moreover, the effect of bandgap energy of the contact surface and the width of the window layer on device performance is discussed. A trade-off of high-efficient SPETE converters is therefore realized between large contact surface bandgap and thin window layer width, to which the rationale lies in the improved process of electron collection facilitated by the enhanced build-in electric field rather than reducing the photon absorption in the window layer. Threshold values for barrier height at the emitting interface are presented to guarantee the ideal voltage-current characteristic. It is found that the threshold values of barrier increase with the increase in temperatures.

为了实现高性能的固态光子增强热电子发射（SPETE）太阳能转换器，在本研究中，因此采用了分级的带隙窗口层，在整个过程中，通过改变Al中Al的组成来产生带隙梯度。带有GaAs吸收器的SPETE转换器的第二层。基于一维稳态方程，建立了一个分析模型，用于分析所研究设备的性能。理论仿真结果表明，不仅能带隙梯度引起的窗口层内建电场降低了接触面复合的损失，而且有效地收集了光子产生的电子，从而提高了转换效率。此外，讨论了接触表面的带隙能量和窗口层的宽度对器件性能的影响。因此，在大的接触表面带隙与薄的窗口层宽度之间实现了折衷的高效SPETE转换器，对此的理由在于增强​​的内置电场促进了电子收集过程的改善，而不是减少了窗口层中的光子吸收。给出了发射界面的势垒高度的阈值，以确保理想的电压-电流特性。已经发现，势垒的阈值随着温度的升高而增加。