(Zoom) APS Seminar: See defects in Perovskites-for more efficient perovskite solar cells, Zhenyi Ni, PhD

See defects in Perovskites-for more efficient perovskite solar cells 

Zhenyi Ni, PhD (Huang Group)

A clean and renewable energy revolution is taking place in United States and across the whole world.  High-efficiency solar cells are needed to drive down the cost of clean energy for an accelerated transition from traditional energy, or mainly from fossil fuel. Metal halide perovskite solar cells are emerging as the most promising candidates for the next-generation solar energy solutions which is much cheaper due to the solution process capability and low cost raw materials. The efficiency of perovskite solar cells have rapidly increased to be > 25%, while any further improvement of the efficiency of perovskite solar cells will rely on deeper understandings on the properties of defects in the perovskite devices to squeeze out all non-radiative charge recombination paths. Unfortunately most common methods for defect characterization in semiconductors are not applicable to perovskites.  Here I will report a new characterization technique to resolve both spatial and energy distribution of defect states and doping in working perovskite solar cells.  This will answer long-standing question like why single crystal perovskite solar cells are not better polycrystalline solar cells.  I will explain some unexpected discovery for the trap distribution, which also points out a direction to further improve the efficiency of perovskite solar cells by reducing both the surface and bulk trap densities in perovskites through new synthesis.

When: March 31, Tuesday 4-5 pm

Join URL: https://unc.zoom.us/j/122535205

 The zoom meeting should be available from 4 pm.  When you log on, please make sure to mute your microphone. During the Q&A, make sure to un-mute yourself if you want to ask questions.