* Title: Spectral Analyses of Stochastic Charge Trapping in Oxide Heterostructures
* Speaker: 이형우 (아주대학교 물리학과 교수)
* Date: 2023. 5. 26.(금) 11:00
* Place: E6-2 #1323
Exploiting oxygen vacancies has emerged as a versatile tool to tune the electronic and optoelectronic properties of complex oxide heterostructures. For the precise manipulation of the oxygen vacancy point defects, the capability of directly probing the defect distribution in nanoscale is essential, but still lacking. In this talk, first, the charge trapping behavior of oxygen vacancies in oxide heterostructures will be introduced. The stochastic charge trapping of the oxygen vacancies results in the characteristic carrier number fluctuation. We employ a classical spectral analysis method to interpret the carrier number fluctuation phenomena. Second, it will be shown that the spectral analysis method can probe the ionization state distribution of oxygen vacancies in oxide heterostructures. Based on the capability and limitation of the classical spectral analyses, lastly, we suggest a novel approach of the machine leaning-assisted spectral analysis method. The specifically-designed machine learning model allow us to evaluate the spatial distribution of the ionized oxygen vacancies from current noise signals. The correlation between the ionization state distribution of the oxygen vacancies and the stochastic charge trapping behavior will be discussed. Our works introduce a powerful strategy to quantitatively probe the spatial distribution of point defects in oxide heterostructures with nm-scale precision.
Inquiry: Prof. Se Kwon Kim(firstname.lastname@example.org) / Prof. Hee Jun Yang (email@example.com)