Single-Crystal Lead-Free Perovskite Nanowire Parallel Arrays for High-Performance Thin-Film Transistors and Integrated Circuits

When electronics and optoelectronics meet in a same affordable device platform, they can enable many unique applications to enhance our life quality. For example, it would be feasible to have a device with multi-functionality that emits and detects light as wellas simultaneously switches current as a transistor for next-generation digital displays. However, until now, the conventional electronic material (i.e. silicon) still cannot satisfy the need of active materials for such a device. The challenge is that there is always a lack of low-cost high-performance materials with the capability not only to generate (or absorb) light but also to have charge carriers transported efficiently. Recently, the advent of organic-inorganic hybrid lead halide perovskite nanomaterials has led to a major step forward in light-emitting diodes (LEDs) and solar cells, and pathed promising avenues for transistors; but at the same time these perovskites are quite restricted by the complexity of preparing organic components, air instability, lead toxicity concern and incompatibility with standard integrated circuit processes (e.g. lithography) for practical utilizations. More importantly, these perovskites are usually polycrystalline with lots of grain boundaries, which make the performance of their electronic devices far behind the optoelectronic counterparts. As a result, there are still many issues and opportunities in the fundamental studies and the performance evaluation of high-performance nanostructured perovskite transistors. In this proposal, we will investigate the direct synthesis of single-crystal, all-inorganic, air-stable and lead-free perovskite (e.g., cesium tin halide and cesium bismuth halide) nanowires and the efficient doping scheme to enhance the nanowire electronic transport properties. Perovskite-compatible fabrication processes will also be studied to achieve the advanced nanowire device structures on silicon, glass and plastic substrates. Utilizing the nanowire printingtechnique, uniform perovskite nanowire parallel arrays will as well be assembled at large scales for the construction and the device performance limit assessment of high performance thin-film transistors and integrated circuits. Combined with the well-knownexcellent optoelectronic properties of perovskite nanostructures for LEDs and solar cells, our ultimate goal is to achieve a versatile and promising device platform for highly-efficient and low-cost integrated optoelectronic circuits and systems that purely base on crystalline, all-inorganic and lead-free perovskite nanowires.