Photocapacitor integrating both energy harvest and storage functions into a single device is a frontier research orientation, which facilitates the efficient and sustainable utilization of green energy. However, the multi-functions in one device and structural complexity of the integrated device, particularly the mismatch between energy harvest and storage units, lead to a relatively large energy loss in the energy storage and output processes. Here, we design a voltage adjustable hybrid supercapacitor (VAHSC) as an energy storage unit of a three-terminal photocapacitor. The VAHSC effectively harmonizes the energy harvest and storage units, resulting in the current, voltage, power, and energy match between both units. The optimal photocapacitor achieves a storage efficiency as high as 98.28% and Joule efficiency of 86.01%, along with excellent charge/discharge cycle stability. The great leap in this efficiency marks a substantial step towards the practical application of solar-charging energy storage integrated devices.

中文翻译：

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光电容器集成了电压可调混合超级电容器和硅太阳能电池，产生 86% 的焦耳效率

将能量收集和存储功能集成到单个器件中的光电容器是一个前沿研究方向，有助于绿色能源的高效和可持续利用。然而，一个器件的多功能性和集成器件的结构复杂性，特别是能量收集和存储单元之间的不匹配，导致能量存储和输出过程中的能量损失相对较大。在这里，我们设计了一种电压可调混合超级电容器（VAHSC）作为三端光电容器的储能单元。VAHSC 有效地协调了能量收集和存储单元，导致两个单元之间的电流、电压、功率和能量匹配。最优的光电电容器实现了高达 98.28% 的存储效率和 86.01% 的焦耳效率，以及出色的充电/放电循环稳定性。这种效率的巨大飞跃标志着太阳能充电储能集成设备的实际应用迈出了实质性的一步。