The need for inexpensive and highly efficient solar cells forces the exploration of new semiconductors which satisfy the photovoltaic criteria. For large scale applications, economic, ecological, chemical and electronic
properties have to be taken into account: Resource abundance, ease of fabrication, especially thin film technologies, long term stability and non-toxicity. The transition metal dichalcogenides (TMDC's) MoS2 and WS2 fulfill all these requirements.
First solid state devices based on untreated WS2 thin films exhibited already reasonable open circuit voltages (up to 550 mV under 85 mW/cm2 AM 1.5 simulated sun illumination) despite a non optimized, planar diode geometry. The properties of the MoS2 and WS2 thin films, which are of photovoltaic interest, are almost identical. They depend on composition, structure and morphology and can be optimized by a suitable choice of deposition parameters.
The aim of the proposed project is to study the solar cell performance of MoS2 and WS2 thin film devices dependent on different preparation techniques and chemical treatments. With respect to device fabrication MoS2 and WS2 films will be deposited on metallic or semiconducting contacts by the following preparation techniques: CVD, MOCVD, chemical deposition, electrochemical deposition, synthesis by solid state reaction, sputtering, and screen printing. With ZnO or ITO as emitter material heterojunctions will be prepared. Chemical treatments and intercalation experiments will be carried out in order to optimize the material and device properties. All the participants in the EURO*TMDC project are experts in thin film preparation and characterization of TMDC's. The EURO*TMDC project brings now an unique opportunity to concentrate both experiences concerning the material properties of TMDC thin films as well as the solar cell device fabrication. Thus, the innovation supported by the European Community will be the development of thin film solar cells containing abundant and non-toxic elements.
Funding SchemeCSC - Cost-sharing contracts