Through using surface diffusion-controlled nucleation & growth, we successfully formed the pattern of Hybrid perovskite thin-film without using any lithography process. By collaborating with Prof. Myungwoong Kim's group, the research has been published in Chemistry of Materials. Also, the work got the Best poster award from Korean Institue of Chemical Engineers.

[1] G Kim, S. An, S.-K. Hyeong, S.-K. Lee, M. Kim*, N. Shin*, Chem. Mater. 31, (2019). [10.1021/acs.chemmater.9b03155]

[2] G. Kim, et al. PREPARATION METHOD FOR PATTERNED PEROVSKITE LAYER AND PEROVSKITE LAYER COMPRISING THE PATTERN PREPARED THEREBY, Korea - Application No.10-2019-0093528.

The most intriguing thing about hybrid perovskite is bandgap tunability, which can be easily done by exchanging halide ion components of the material.

Through integrating patterned hybrid perovskite film and vapor phase halide ion exchange reaction, we not only but demonstrated the bandgap exchange, but also confirmed that anion exchange reaction approximately follows Avrami kinetics.

I also demonstrated stability improvement of bromine-exchanged film in ambient conditions through fabricating it as a photodetector and measuring its performance via proposing a halide/oxygen diffusion model to explain this phenomenon.

[1] G. Kim, S. An, S.-K. Hyeong, S.-K. Lee, M. Kim, N. Shin*, Small 2006737 (2021). [10.1002/smll.202006737]