Project Details
Projekt
Control over grain size and crystallinity: Role of trap states in perovskites II (Perocryst)
Subject Area
Experimental Condensed Matter Physics
Physical Chemistry of Solids and Surfaces, Material Characterisation
Physical Chemistry of Solids and Surfaces, Material Characterisation
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 423660474
The project “Control over grain size and crystallinity: Role of trap states in perovskites (II) (Perocryst)” is a highly interdisciplinary project between physics and materials science / physical chemistry coupling the expertises of Prof. Lukas Schmidt-Mende (device physics, nanoscience) and Prof. Sabine Ludwigs (controlled crystallization, morphology tuning, materials science). The main objective of the project is to gain a deeper understanding and control of nucleation and crystal growth of high quality perovskite films to ultimately improve solar cell performance in terms of reproducibility, efficiency and stability. The crystallization shall be manipulated and guided towards single crystalline thin perovskite films with ideally no defects and grain boundaries. Systematic correlations of the number of grain boundaries and size of domains with respect to their role as trap states shall be established. In the project we will focus on material processing and post-annealing, in depth investigation of the parameters influencing the film crystallization, such as topographically & chemically patterned substrates and electric field guided growth, and finally the opto-electronic characterization, including (anisotropic) charge transport, solar cell performance and dynamic characterization of transport and recombination. The key to success of our strategy is that our preparation methods allow a reproducible perovskite film formation with tailored number of grain boundaries. Our post-annealing approaches allow a direct means to tune nucleation and guide crystal growth. Single crystals in films are ultimately targeted as perfect candidates for solar cells. The combination of in-situ characterization tools for the crystal growth and in depth-characterization on films allows a systematic approach to improve the film quality and understand the growth mechanism and its governing parameters. With our project, we aim to obtain single crystalline films or films with a low number of grain boundaries / low nucleation densities. We want to establish design rules for best quality crystallized films which shall enable us to conclude on structure-function relationships between film quality and crystal structure, stability and device performance in solar cells.
DFG Programme
Priority Programmes
