Perovskite thin film solar cells from multi-stage dry reactions

本项目的目标是开发用于太阳能电池的多组分ABX3钙钛矿薄膜的多阶段全真空生长过程并进行动力学量化。对于多组分钙钛矿薄膜，我们指的是合金薄膜中的多个阳离子和多个阴离子。与同时共蒸发相比，多阶段工艺更适合于工业制造。该工艺应为全干法。不同的薄膜生长阶段可以是(A)前驱体蒸汽反应，其中固态前驱体薄膜与形成钙钛矿膜的蒸汽反应。(B)扩散耦合反应，其中两个或多个固态前驱体薄膜通过化学扩散反应。(C)交换反应，其中一个组分(阴离子或阳离子)在热处理过程中被另一个组分完全或部分交换。应研究最新的铅基钙钛矿和未来的锡基化合物。使用在受控温度和流量下进行的反应过程，可以量化反应常数、扩散常数和活化能。本项目采用的主要实验方法是实时原位X射线衍射，它提供了薄膜生长过程中的相形成过程的信息。

The goal of this project is the development and kinetic quantification of multi-stage all-vacuum growth processes of multi-component ABX3 perovskite thin films for solar cells. With multicomponent perovskite films we mean multi-cations and multi-anions in an alloy film. In contrast to simultaneous co-evaporation, multi-stage processes are preferable for industrial fabrication. The processes shall be all-dry. Different film growth stages can be(a) Precursor vapor reaction where a solid state precursor film reacts with vapor forming the perovskite film. (b) Diffusion couple reaction where two or more solid state precursor films react by chemical diffusion.(c) Exchange reaction where one component (anion or cation) is fully or partly exchanged by another component during annealing processes.State-of-the-art Pb-based perovskites but also prospective Sn-based compounds shall be studied. Using reaction processes performed under controlled temperature and fluxes, reaction constants, diffusion constants, and activation energies will be quantified. The main experimental method employed in this project is in-situ X-ray diffraction in real-time which gives information on the phase formation processes during thin film growth.