Understanding losses in halide perovskite thin films

I am interested in identifying the intrinsic source of losses in polycrystalline thin films of halide perovskites with the aim to improve our understanding toward better optoelectronics properties, and device performances. I work very closely across material synthesis, thin film deposition methods, developing a new characterization technique, and optoelectronics theory/modelling.

One example of works that I am currently working on is understanding the grain boundary effect in halide perovskites. We first developed thin film deposition method to control the grain size without affecting much the bulk and surface quality. Second, we determined the grain size using electron back-scattered diffraction technique where the result found to be deceiving compared to those obtained based on optical or scanning electron images. Third, we statistically analysed a range of significant losses (minority carrier lifetime, mobility, and diffusion length) contributed by the grain boundary. Finally, using Fourier decomposition, and finite element methods, we modelled the implications of such findings on solar cell characteristics, and thin film photoluminescence quantum yield.

Picture: Deceiving features on the grain boundary under SEM (left) versus EBSD (right).
The scale bars are 50 micron

Brainpower: Gede Adhyaksa