Microstructure and functionality in thin film solar cells from sustainable materials
The project is to use state of the art electron microscopy alongside the synthesis effort in order to accelerate the control and deployment of the Cu-(Sb,Bi)-S family of materials as potential sustainable new semiconductors for PV applications. The student will synthesise thin films using the post-growth sulfurisation method, the metal films being made by sputtering and by evaporation. Sulfurisation will be done in a two zone furnace so as to control the over-pressure of sulphur. The pressure of inert gas is also known to be important in controlling the loss of volatile metal sulfides from the film – this process variable will also be adjusted. A range of structural characterisation methods will be used to determine the systematic influence of process variables on the phase purity and microstructural properties of the films. It is an aim of the project to establish protocols for the synthesis of high quality films and of finished PV devices. The student will go on to evaluate finished devices using electron microscope methods e.g. to determine the interface quality and grain boundary distributions as well as micro-resolved functionality. They will also be responsible for the characterisation of device performance. The student will use XRD, TEM, FIB, EDX and EELS, and device characterisation methods. It is expected that they will become an expert in structural and chemical evaluation of both solar energy materials and solar cells.