In photoelectrochemical (PEC) water-splitting systems, photoelectrode configuration is a key ingredient to obtain the high conversion efficiency. To effectively guide the device fabrication, the intrinsic multi-domain physics and mechanisms (e.g., light absorption in optical domain and carrier generation/separation/transport/collection in electrical domain) have to be uncovered, which requires the advanced optoelectronic simulation. In this study, focusing on the Si/α-Fe₂O₃ heterojunction photoanodes, we present a comprehensive optoelectronic study on the microscopic photoelectric processes inside the dual-absorbable photoanode. We systematically simulate the carrier generation, separation, recombination, and collection of the electron-hole pairs so that the complete optoelectronic responses of this kind of electronic devices can be obtained. The systems under consideration include n-Si/α-Fe₂O₃/electrolyte, p-Si/α-Fe₂O₃/electrolyte, and α-Fe₂O₃/electrolyte systems in order to uncover the intrinsic physics as well as find the optimal device designs. We obtain the spectra of light absorption, output- and recombination-photocurrent profiles, along with the current-voltage characteristics under dark and illumination conditions. Moreover, the energy band diagram under various system configurations are calculated and compared. The optoelectronic simulation and investigation provide a convenient methodology for the design of PEC-related systems for improved performance.

在光电化学（PEC）水分解系统中，光电极配置是获得高转换效率的关键因素。为了有效地指导器件制造，必须揭示固有的多域物理和机制（例如，光域中的光吸收以及电域中的载流子产生/分离/传输/收集），这需要先进的光电模拟。在这项研究中，着眼于硅/上的α-Fe ₂ ö ₃异质结光电阳极，我们对双吸收型光阳极内部的微观光电过程进行了全面的光电研究。我们系统地模拟了电子-空穴对的载流子产生，分离，重组和收集，从而可以获得此类电子设备的完整光电响应。所考虑的系统包括正的Si /的α-Fe ₂ ö ₃ /电解质，的p-Si /的α-Fe ₂ ö ₃ /电解质和的α-Fe ₂ ö ₃/电解质系统，以发现内在的物理原理，并找到最佳的器件设计。我们获得了光吸收，输出和复合光电流曲线的光谱，以及在黑暗和光照条件下的电流-电压特性。此外，计算并比较了各种系统配置下的能带图。光电仿真和研究为设计与PEC相关的系统提供了一种方便的方法，以提高性能。