Copper Sulfide Assisted Recrystallization of Cu-poor CuInS2 Observed in-situ by Polychromatic X-ray Diffraction

Abstract

AbstractThe microstructural changes during heating of bi-layers of Cu-poor CuInS2 and CuS under different sulfur excess conditions were studied. This was done by means of energy dispersive X-ray diffraction of polychromatic synchrotron radiation in a vacuum setup where the sulfur pressure conditions can be controlled. Understood as the formation of a new microstructure, the recrystallization of the Cu-poor CuInS2 phase was characterized by a change in the reflection profile (from Cauchy-type to Gauss-type), the reduction of the breadth and a subsequent normalized-intensity increase of the 112 reflection. The Cauchy component of the breadth was used to monitor the recrystallization under different sulfur and heating rate conditions. The main results are: a) Cu availability for the consumption of the CuIn5S8 phase is a pre-requisite for recrystallization, b) in presence of the Cu2-xS phase, increased sulfur pressure enhances recrystallization.