Xiaoxi Wu (SIMES Special Seminar)

Date(s) - May 11 2015
9:30 AM - 10:30 AM

Room 335, McCullough Building


Charge/Exciton Dynamics, Trapping and Lasing in Lead Iodide Perovskites

Xiaoxi Wu

Columbia University

Methyl ammonium lead iodide (3D MAPbI3) perovskite is a very promising semiconductor for low cost and high efficiency thin film solar cells. When adding butylammine, the lead iodide building blocks can self-assemble into 2D structures. Studies of the photo-generated species, the carrier and/or exciton interactions and the trapping process are important for understanding the solar cell working mechanism and designing the next generation of high efficiency solar cells. Even though many studies are reported, some fundamental questions remain unsolved. What is the nature of the photogenerated species? Are they carriers or excitons? How do they interact? Will 2D quantum confinement affect their photophysical properties? And where are the traps? In this talk, I will address these questions with my recent studies on 3D and 2D lead iodide perovskites using Time-Resolved Transient Absorption Spectroscopy. Our recent study on perovskite single crystal nanowire lasing will also be demonstrated.

graphic accompanying absttract of Xiaoxi Wu's seminar