Logo image
Distinguishing Thermal and Electronic Effects in Ultrafast Optical Spectroscopy Using Oxide Heterostructures
Journal article

Distinguishing Thermal and Electronic Effects in Ultrafast Optical Spectroscopy Using Oxide Heterostructures

Sergey Y. Smolin, Amber K. Choquette, Jiayi Wang, Steven J. May and Jason B. Baxter
Journal of physical chemistry. C, v 122(1)
11 Jan 2018

Abstract

Chemistry Chemistry, Physical Materials Science Materials Science, Multidisciplinary Nanoscience & Nanotechnology Physical Sciences Science & Technology Science & Technology - Other Topics Technology
Measuring time-resolved photoexcited properties in semiconductors is critical to the design and improvement of light-harvesting devices. Although ultrafast pump probe spectroscopy offers a promising route to understand carrier recombination mechanisms and quantify, lifetimes, thermal contributions to the transient optical response can be significant and need to be properly accounted for to isolate carrier-induced contributions. We demonstrate the use of broadband ultrafast optical spectroscopy on type heterostructures as a means to isolate-transient effects that are solely thermal in nature. Specifically, we use transient absorption,and reflectance spectroscopy to measure the time-resolved optoelectronic changes in photoexcited epitaxial bilayers of LaFeO3/LaMnO3 and monolithic thin film's of these materials:, Experiments and complementary numerical modeling reveal that thermal effects dominate the transient absorption-and reflectance spectra above the band gap. Fitting the dynamics with a thermal diffusion model yields thermal conductivities of 6.4 W m(-1) k(-1) for LaFeO3 and 2.2 W m(-1) k(-1) for LaMnO3. In LaFeO3, an additional photoinduced absorption feature below the band gap at X1.9 eV is assigned primarily to photoexcited carriers and persists for over 3 ns. This work provides a direct demonstration of how thermal and electronic contributions can be separated in transient optical spectroscopies, enabling new insights into dynamical optical properties of semiconductors.

Metrics

6 Record Views
25 citations in Scopus

Details

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Web of Science research areas
Chemistry, Physical
Materials Science, Multidisciplinary
Nanoscience & Nanotechnology
Logo image