Making connections – A study of electrode materials for single CsPbBr3 nanowire devices

Sammanfattning

The last decade and a half has seen intense research efforts into metal-halide perovskite (MHP) materials, as researchers have come to appreciate their excellent photo-electrical properties such as good radiative recombination rates and light absorption. As part of these efforts MHP-devices of different morphologies have been developed. Notably the enhanced nanophotonic effects of nanowire (NW) morphologies have led researchers to consider MHP NWs as a suitable structure for optoelectronic devices. The inherent susceptibility of MHP-materials to a variety of degradation pathways does place limitations on what techniques are appropriate for fabricating devices, however, including on the ability to introduce dopants in order to create heterostructures. This places greater emphasis on the importance of finding suitable contact materials in order to create efficient devices. This report, building upon previous research into single CsPbBr3 NWs, provides an overview of the performance of single NW devices fabricated with Ti, Ag, TiO2 and Pd, with the goal of evaluating the suitability of these materials for use as contacts in single NW devices. These results in particular highlight Pd as a suitable contact material, since it minimizes the otherwise ubiquitous hysteresis observed in MHP-materials and shows very linear I-V characteristics under illumination, suggesting that it forms a more ohmic contact than other materials.