Silicon photovoltaic cells functionalized with water-splitting electrocatalysts are promising candidates for unassisted water splitting. In these devices, the total surface of silicon solar cells is covered with electrocatalysts, causing issues with (i) stabilizing silicon solar cells in water and (ii) device efficiency due to parasitic optical absorption in electrocatalysts. We describe and validate a water-splitting device concept using a crystalline silicon solar cell where the front side is covered with an insulating Si₃N₅ antireflection coating. The Ag contacts, fired through the antireflection coating, are removed and subsequently substituted with NiFe layered double hydroxide (LDH) or Cu/NiFe-LDH electrocatalysts. In this device, only the site of Ag contacts, nearly 2% of the total device area, is covered by the electrocatalyst. We found that this small area of the catalyst does not limit device performance and the addition of a Cu interlayer between Si and NiFe-LDH improves device performance and stability. The unassisted water-splitting efficiency of 11.31%, measured without separating the evolved gases, is achieved using a device composed of three series-connected silicon solar cells and an NiFe-LDH/Cu/Ni-foam counter electrode in a highly alkaline electrolyte.

中文翻译：

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使用铜和双功能NiFe电催化剂稳定的标准硅太阳能电池进行无辅助分水

用水分解电催化剂功能化的硅光伏电池是无助水分解的有希望的候选者。在这些装置中，硅太阳能电池的整个表面被电催化剂覆盖，导致以下问题：（i）稳定水中的硅太阳能电池，以及（ii）由于电催化剂中的寄生光吸收而导致的装置效率。我们描述并验证了使用晶体硅太阳能电池的水分解装置的概念，该太阳能电池的正面被绝缘Si ₃ N ₅覆盖防反射涂层。除去通过抗反射涂层烧制的Ag触点，然后用NiFe层状双氢氧化物（LDH）或Cu / NiFe-LDH电催化剂代替。在该装置中，只有Ag接触的位置（几乎占装置总面积的2％）被电催化剂覆盖。我们发现催化剂的这一小面积并不限制器件性能，并且在Si和NiFe-LDH之间添加Cu中间层可改善器件性能和稳定性。使用由三个串联连接的硅太阳能电池和NiFe-LDH / Cu / Ni泡沫反电极在高碱性电解液中组成的装置，可实现不分离逸出气体而测得的11.31％的无助水分解效率。