Pulsed Laser Deposition of Novel Spinel Materials for Photovoltaic Conversion

While all traditional photovoltaic materials are covalent compounds with coordination number 4, currently the most progressive materials -hybrid halide perovskites -have coordination number 6 and are ionic.This can be the key to success, especially regarding surface electronic properties, which are essential for polycrystalline semiconductors.This motivates us to explore completely new materials -cubic lithium thiospinels -and compare them with the former.Li thiospinels are prepared from stoichiometrically mixed precursors as a pellet in a nitrogen-filled glovebox.This tablet serves as a target in Pulsed Laser Deposition (PLD) and a special chamber is constructed that avoids air exposure of the precursor tablet during the loading.Thin films of lithium thiospinels are deposited on glass substrates and they are characterized by X-ray diffraction and optically by Photothermal Deflection Spectroscopy for accurate determination of absorption edge.Results are promising and demonstrate the validity of this approach.