Harnessing solar energy to drive photoelectrochemical reactions is widely studied for sustainable fuel production and versatile energy storage over different timescales. However, the majority of solar photoelectrochemical cells cannot drive the overall photosynthesis reactions without the assistance of an external power source. A device for simultaneous and direct production of renewable fuels and electrical power from sunlight is now proposed. This hybrid photoelectrochemical and photovoltaic device allows tunable control over the branching ratio between two high-value products of solar energy conversion, requires relatively simple modification to existing photovoltaic technologies, and circumvents the photocurrent mismatches that lead to significant loss in tandem photoelectrochemical systems comprising chemically stable photoelectrodes. Our proof-of-concept device is based on a transition metal oxide photoanode monolithically integrated onto silicon that possesses both front- and backside photovoltaic junctions. This integrated assembly drives spontaneous overall water splitting with no external power source, while also producing electricity near the maximum power point of the backside photovoltaic junction. The concept that photogenerated charge carriers can be controllably directed to produce electricity and chemical fuel provides an opportunity to significantly increase the energy return on energy invested in solar fuels systems and can be adapted to a variety of architectures assembled from different materials.

广泛研究了利用太阳能来驱动光电化学反应，以可持续地生产燃料，并在不同的时间尺度上实现多功能的能量存储。但是，如果没有外部电源的帮助，大多数太阳能光电化学电池无法驱动整个光合作用反应。现在提出了一种用于从阳光同时直接生产可再生燃料和电力的装置。这种混合式光电化学和光生伏打装置可实现对太阳能转换的两个高价值产品之间的分支比率的可调控制，需要相对简单地修改现有的光生伏打技术，并规避了光电流不匹配的问题，从而导致包括化学稳定的串联光电化学系统的重大损失光电极。我们的概念验证设备基于单片集成到同时具有正面和背面光伏结的硅上的过渡金属氧化物光电阳极。这种集成的组件无需外部电源即可自发进行总的水分解，同时还能在背面光伏结的最大功率点附近发电。光生电荷载流子可被控制地产生电能和化学燃料的概念提供了一个机会，可以显着提高太阳能电池系统投资能量的能量回报，并且可以适应由不同材料组装而成的各种架构。