发光学报2025，Vol.46Issue(7)：1271-1282,12.DOI:10.37188/CJL.EN20240013
确定半导体禁带宽度的光谱方法
Optical Spectroscopy Methods for Determining Semiconductor Bandgaps
摘要
Abstract
Although there are numerous optical spectroscopy techniques and methods that have been used to extract the fundamental bandgap of a semiconductor,most of them belong to one of these three approaches:(1)the excitonic absorption,(2)modulation spectroscopy,and(3)the most widely used Tauc-plot.The excitonic absorption is based on a many-particle theory,which is physically the most correct approach,but requires more stringent crystalline quality and appropriate sample preparation and experimental implementation.The Tauc-plot is based on a single-particle theo-ry that neglects the many-electron effects.Modulation spectroscopy analyzes the spectroscopy features in the derivative spectrum,typically,of the reflectance and transmission under an external perturbation.Empirically,the bandgap ener-gy derived from the three approaches follow the order of Eex＞EMS＞ETP,where three transition energies are from exci-tonic absorption,modulation spectroscopy,and Tauc-plot,respectively.In principle,defining Eg as the single-elec-tron bandgap,we expect Eg＞Eex,thus,Eg＞ETP.In the literature,ETP is often interpreted as Eg,which is conceptual-ly problematic.However,in many cases,because the excitonic peaks are not readily identifiable,the inconsistency be-tween Eg and ETP becomes invisible.In this brief review,real world examples are used(1)to illustrate how excitonic absorption features depend sensitively on the sample and measurement conditions;(2)to demonstrate the differences between Eex,EMS,and ETP when they can be extracted simultaneously for one sample;and(3)to show how the popular-ly adopted Tauc-plot could lead to misleading results.Finally,it is pointed out that if the excitonic absorption is not ob-servable,the modulation spectroscopy can often yield a more useful and reasonable bandgap than Tauc-plot.关键词
半导体材料/禁带宽度/激子吸收/调制光谱/Tauc图Key words
semiconductor material/bandgap/excitonic absorption/modulation spectroscopy/Tauc plot分类
信息技术与安全科学引用本文复制引用
张勇..确定半导体禁带宽度的光谱方法[J].发光学报,2025,46(7):1271-1282,12.基金项目
北卡罗来纳大学夏洛特分校Bissell杰出教授捐赠基金Supported by Bissell Distinguished Professor Endowment Fund at UNC-Charlotte （）
