Within the framework of the three-year project “SOLAMO”, financed by the Ministry of the Environment of Baden-Württemberg, the two thin-film solar technologies based on Cu(In,Ga)Se2 (copper, indium, gallium, selenium, in short: CIGS) and perovskites are to be further developed in parallel by using innovative production approaches. The goal is to bring about the prerequisites for a future perovskite/tandem structure (see also demonstrator for CIGS perovskite tandem module).
A new vacuum laboratory coating system was purchased for CIGS solar cells. In contrast to an existing system, which is used at ZSW to develop highly efficient solar cells, this system is designed to be particularly flexible: It can be used to produce high-quality absorbers on a surface area of up to 10 x 10 cm2 at relatively low temperatures of ≤ 450 °C as well as at high temperatures of ≥ 650 °C. The researchers are able to specifically test and pre-develop certain industry-relevant parameters such as doping, deposition rates or substrate temperature. One example would be determining the maximum possible CIGS deposition rate that can still be achieved with the co-evaporation process, in which all elements are deposited onto the substrate in one step. After the construction and installation of the plant, good cells with an efficiency of 16% were already produced in the first experiments of 2017. In addition to the production of CIGS solar cells on various substrates such as plastic film, metal foil or metal oxides and the research of highest deposition rates, the “SOLAMO” project is also dedicated to the vacuum-free production of perovskite absorbers from a solution. The aim is to achieve stable, in other words hysteresis-free, efficiencies of more than 14%. Lead-free absorbers will be examined as well, in order to finally produce functional, monolithically interconnected small modules.