UNSW School of Photovoltaic & Renewable Energy Engineering
Scanning probe microscope: A powerful tool for imaging nanoscale charge transport properties
Jae Sung Yun - UNSW School of Photovoltaic and Renewable Energy Engineering


Jae Sung Yun, at UNSW SPREE, 21 November 2019

Jae Sung Yun (51Min)

UNSW School of Photovoltaic and Renewable Energy Engineering

Jae Sung Yun speaks at UNSW SPREE

Abstract

In this seminar, I will introduce scanning probe microscope (SPM) techniques such as conductive atomic force microscopy (c-AFM) and scanning Kelvin probe force microscopy (KPFM) which are a powerful tool to visualize local charge transport properties with resolutions in the order of atomic/nanometer scales. SPM image is constructed by moving a sharp probe across a sample surface while using a feedback mechanism to maintain the tip−sample separation. As the tip is scanned along the surface, electronic, topographical, force, optical, and other properties are mapped out at resolutions that range from the atomic scale up to tens of nanometres. It enables identifying morphological features such as defects in solar cells as well as extracting various electrical properties including the location of the pn junction, charge separation/generation, and trapped charges. In this presentation, the nanoscale imaging results on halide perovskite solar cells, Si solar cells, and kesterite solar cells will be mainly presented and discussed. Also, I will talk about how KPFM can be effectively utilized in tandem or multi-junction solar cells and indoor solar cells.



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Brief Bio

Dr. Jae Sung Yun is an Australian Centre for Advanced Energy postdoctoral fellow and a lecturer at School of Photovoltaic and Renewable Energy Engineering (SPREE) at University of New South Wales, Australia. He earned his Bachelor of Materials Science and Engineering (MSE) at Yonsei University, Korea in 2008 and Master of philosophy in MSE at University of New South Wales in 2010. Afterwards, he completed his PhD study on fabrication and characterization of polycrystalline thin-film solar cells in SPREE under the supervision of Professor Martin Green in 2015. Following that he joined perovskite solar cell group in the same department as a postdoctoral fellow until 2017. After obtaining his fellowship in 2018, he exclusively works on functional nanoscale imaging using scanning probe microscope in halide perovskites, kesterite, and Si solar cells, discovering and characterizing nanoscale charge transport properties. He has published 34 peer reviewed journals and 4 conference papers.