Photoluminescence intermittency in micron-size hybrid lead halide perovskites by Prof. Shaibal Sarkar

Location and Date: 
Wednesday,August 09, 2017,4:00 pm, LT 101
Organic-metal-Halide perovskite materials recently attracted immense attention due to its unique optoelectronic properties, easy and versatile synthesis routes and its applicability in photovoltaic and light emitting devices. The existing literature demonstrates that the device performances depend heavily on the film morphology, shape and size of the crystal and of course the stoichiometry of the synthesized material.
In this presentation, I will be discussing some interesting and unique optoelectronic properties of some “bad” perovskite materials when it is either synthesized under non-ideal conditions or as non-stoichiometric which is not ideal for high performance devices. Here I will aim to justify a distinct correlation between the surrounding ambient and the PL intermittency of isolated and conjugated formamidinium lead bromide (FAPbBr3) microcrystals having dimension higher than the excited carrier diffusion length. A custom-built spectrally resolved epi-fluorescence microscopy is used to capture the wide-field optical emission properties of the material. With adequate experiments, we are able to describe the role of photoelectrochemically generated trap states that plays a deterministic role in PL intermittency. We further aim to establish a direct correspondence between the material degradation and the blinking.
Prof. Shaibal K Sarkar is currently an Associate Professor at Department of Energy Science and Engineering, Indian Institute of Technology Bombay. He did his PhD from Weizmann Institute of Science, Israel in the year 2005. Later he joined University of Missouri at Roll as Post doctorate researcher. Before joining to IITB he was working as postdoc fellow at University of Colorado at Boulder in collaboration with National Renewable Energy Laboratory, Golden Colorado.