Design of Structural and Chemical Disorder in Metal Oxide Thin Films for Enhanced Light Absorption (EnLight)

跨学科项目EnLight将开发创新的材料改性工艺，通过原子层沉积（ALD）和化学气相沉积（CVD）技术生长的SnO2， TiO2， CeO2薄膜的激光辅助周期性表面结构（相关无序）来改善金属氧化物半导体薄膜的光管理性能。此外，将对上述金属氧化物表面进行等离子体辅助表面还原，以诱导薄膜中的价交换和化学梯度，这已被报道大大改变了光学和电学性质。激光束的聚焦性质和等离子体羽流的随机性质将允许在光学和电学性质方面评估量身定制的无序与随机无序。这项工作的重点是证明由激光辅助金属氧化物纳米层合物图图化产生的相关结构紊乱和由化学转化局部引起的化学（相）紊乱，这些化学转化可以产生复合结构，例如，嵌入在氧化物基体中的金属纳米结构可以通过激光照射将双金属氧化物（例如尖晶石M'M''2O4）转化为M/M2O3复合材料来改变光学性质，如折射率和雾霾值。从采用CVD和ALD方法制备低缺陷浓度的相纯薄膜开始，进行激光和等离子体改性，并通过深入的化学、结构和功能表征以及激光照射效应的模拟来支持，以详细了解无序形成的潜在反应机制。最后，结构衬底将作为有机铅卤化物钙钛矿太阳能电池的组成部分进行测试，以阐明在工作原型中定制无序的潜力。在这个项目中获得的专业知识将为1839优先计划的其他成员提供一个平台，用于定制金属氧化物薄膜的无序，这可以扩展到柔性基板。

The interdisciplinary project - EnLight - will develop innovative materials modification processes to improve the light-management properties of metal oxide semiconductor films by laser-assisted periodic surface structuring (correlated disorder) of SnO2, TiO2, CeO2 films grown by atomic layer deposition (ALD) and chemical vapor deposition (CVD) techniques. In addition, plasma-assisted surface reduction of the above-mentioned metal oxide surfaces will be undertaken to induce valence-exchange and chemical gradient in the films that have been reported to drastically alter the optical and electrical properties. The focused nature of laser beams and random nature of plasma plume will allow evaluating tailored disorder against random disorder in terms of optical and electrical properties. This effort is focused to demonstrate that correlated structural disorder created by laser-assisted patterning of metal oxides nanolaminates and chemical (phase) disorder locally induced by chemical transformations that can create composite structures, for instance, metal nanostructures embedded in oxide matrices that can modify the optical properties such as refractive index and haze value, by transforming bimetallic oxides (e.g. spinels M'M''2O4) into M/M2O3 composites by laser irradiation. Starting from the fabrication of phase pure thin films with low defect concentration using CVD and ALD approaches, laser and plasma modification will be carried out, supported by in depth chemical, structural and functional characterization as well as simulation of laser irradiation effects to gain a detailed insight into the underlying reaction mechanisms of disorder formation. Finally the structured substrates will be tested as components in organo-lead-halide perovskite solar cells to elucidate the potential of tailored disorder in a working prototype. The expertise gained in this project will serve as a platform for other members of the Priority Program 1839 for tailored disorder of metal oxide thin films, which can be extended to flexible substrates.