DFG Research Unit 2857

Copper Iodide as Multifunctional Semiconductor

P02: Chemical Routes to CuI and Related Compounds
as Thin Films and Bulk Material

Prof. Dr. Harald Krautscheid

Copper(I) iodide (CuI) is a p-type semiconductor with a large band gap and high (hole) conductivity, at the same time CuI is transparent in the visible spectral range. Therefore, with respect to its use in (transparent) electronics, there is currently great interest in p-type-CuI as thin films. Within the Research Unit FOR 2857, the focus of this project is on various chemical synthesis routes for the preparation of thin films as well as single crystals of CuI. In line with the optimization of layer homogeneity and surface morphology, investigations on the targeted control of material properties by doping and solid solution formation with related compounds are being advanced. Thin film formation with control of material properties will be studied by the different possibilities of metal-organic chemical vapor deposition (MOCVD) and close-distance sublimation (CDS). Fundamental investigations concern the influence of dopant sources, substrate, synthesis conditions during the growth process and post-treatment on optical, electrical and mechanical properties of the obtained crystalline and epitaxial CuI thin films. For comparative studies of strain-free doped CuI single crystals as well as CuI-based mixed crystals will be grown. By combining the different processes and materials, the fabrication of defined p-n junctions based on CuI will be investigated.