Optical interference is used to enhance light–matter interaction and harvest broadband light in ultrathin semiconductor absorber films on specular back‐reflectors. However, the high‐temperature processing in oxygen atmosphere required for oxide absorbers often degrades metallic back‐reflectors and their specular reflectance. In order to overcome this problem, a newly developed film flip and transfer process is presented that enables high‐temperature processing without degradation of the metallic back‐reflector and without the need of passivation interlayers. The film flip and transfer process improves the performance of photoanodes for photoelectrochemical water splitting comprising ultrathin (<20 nm) hematite (α‐Fe₂O₃) films on silver–gold alloy (90 at% Ag–10 at% Au) back‐reflectors. Specular back‐reflectors are obtained with high reflectance below hematite films, which is necessary for maximizing the productive light absorption in the hematite film and minimizing nonproductive absorption in the back‐reflector. Furthermore, the film flip and transfer process opens up a new route to attach thin film stacks onto a wide range of substrates including flexible or temperature sensitive materials.

中文翻译：

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薄膜翻转和转移过程可增强镜面背反射器上超薄吸收膜的光收集

光学干涉用于增强光-物质相互作用，并在镜面后向反射器上的超薄半导体吸收膜中收集宽带光。但是，氧化物吸收剂需要在氧气气氛中进行高温处理，这通常会使金属背反射器及其镜面反射率降低。为了克服这个问题，提出了一种新开发的薄膜翻转和转移工艺，该工艺能够进行高温处理而不会降低金属背反射器的性能，也不需要钝化中间层。薄膜翻转和转移过程提高了包含超薄（<20 nm）赤铁矿（α‐Fe ₂ O ₃）银-金合金（90 at％Ag-10 at％Au）后反射镜上的薄膜。获得镜面反射镜的反射率高于赤铁矿膜，这对于最大化赤铁矿膜中的生产性光吸收和最小化反射镜中的非生产性吸收是必要的。此外，薄膜翻转和转移过程开辟了一条新途径，可以将薄膜叠层附着到包括柔性或对温度敏感的材料在内的各种基材上。