Transport layers for thin film optoelectronic devices based on lead halide perovskites

Within an unprecedented short time, lead halide perovskites have been proven to be viable candidates for active material in future optoelectronic devices. Starting from their application in thin film solar cells with record high power conversion efficiencies, these class of perovskites have been integrated with great success in photodetectors, transistors, light emitting diodes and lasers. It is the target of an optoelectronic device to have an optimal conversion of photon energy into electrical energy or vice versa. Charge transport layers are an essential part to ensure high performance. Besides ensuring a high carrier mobility, they need to contribute to effective interfaces between electrical contacts on one side and the perovskite layer on the opposite. Furthermore, these layers exhibit very low extinction coefficients in the relevant wavelength range and their processing conditions are compatible with the other device materials. At imec and Energyville we develop state-of-the-art large area solar cells and modules for maximum power conversion efficiencies, sub-micrometer pixels for high resolution imagers, and ultra-bright light emitting diodes for micro-displays and photonic circuits – all based on the same class of perovskites. It is the target of this PhD, to further improve these devices by developing new layer architectures and fabrication processes with a focus on transport layers. Based on a wide range of experience on solution and vacuum based processes of oxides and organic materials, we want to develop transport layers for an optimized charge extraction in tandem solar cells and photodetectors. On a later stage, light emitting diodes and lasers can be an extension of the research applications.