The past two decades have witnessed the enormous success of metal halide perovskite semiconductors in various optoelectronic devices, like solar cells, LEDs, and most recently transistors, due to an ideal set of optoelectronic properties and processing capability. In particular, considering the urgent demand for high-mobility p-type semiconductors, metal halide perovskite provides a new opportunity to create CMOS circuits in a low-temperature and cost-effective way. Despite certain performance improvements that have been achieved through material design, film processing, and device engineering, a critical understanding of the key properties and potential of these emerging materials for transistor application remains lacking. Therefore, we intend to develop halide perovskite semiconductors for high performance p-type thin-film transistors for commercialization. This project mainly studies the topics below but not limited to this.