Organic semiconductor light absorbers are receiving attention for their potential application in photoelectrochemical (PEC) cells for renewable fuels generation. Key to their advancement is precise control of the interfaces between charge-selective contacts, absorber layers, and electrocatalysts, while maintaining compatibility with an aqueous electrolyte environment. Here we demonstrate a new process for low-temperature atomic layer deposition (ALD) of TiO₂ onto a P3HT:PCBM polymer blend surface for stable high-performance organic PEC photocathodes. This ALD TiO₂ layer provides three key functions: 1) formation of an electron-selective contact to the polymer to enable photovoltage and photocurrent generation, 2) a robust interface for conducting charge between the photoabsorber and electrocatalyst layers, and 3) a pinhole-free barrier to water penetration, preventing corrosion of the underlying materials. The resulting device based on the architecture CuI/P3HT:PCBM/TiO₂/RuOx showed excellent performance and stability during PEC hydrogen-evolution. More broadly, the achievement of ALD film formation on a polymer surface opens doors in the field of functional organic–inorganic electronic interfaces.

中文翻译：

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通过低温原子层沉积TiO ₂稳定有机光电阴极

有机半导体光吸收剂因其在可再生燃料产生的光电化学（PEC）电池中的潜在应用而受到关注。它们前进的关键是精确控制电荷选择触点，吸收层和电催化剂之间的界面，同时保持与水性电解质环境的相容性。在这里，我们演示了将TiO ₂低温原子层沉积（ALD）到P3HT：PCBM聚合物共混物表面上的新工艺，以稳定的高性能有机PEC光电阴极。该ALD TiO ₂该层提供了三个关键功能：1）与聚合物形成电子选择性接触以实现光电压和光电流的产生； 2）坚固的界面，可在光吸收层和电催化剂层之间传导电荷，以及3）对水无针孔的阻挡层渗透，防止底层材料腐蚀。所得的基于CuI / P3HT：PCBM / TiO ₂ / RuOx体系结构的器件在PEC氢演化过程中表现出出色的性能和稳定性。更广泛地讲，在聚合物表面上形成ALD膜的实现打开了功能性有机-无机电子界面领域的大门。