Clarifying the atomic origin of electron killers in β-Ga_(2)O_(3) from the first-principles study of electron capture rates  

作　　者：Zhaojun Suo Linwang Wang Shushen Li Junwei Luo 

机构地区：[1]State Key Laboratory of Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Semiconductors》2022年第11期61-69,共9页半导体学报（英文版）

基　　金：This work was supported by the National Key Research and Development Program of China under Grant No.2018YFB2200105;the Key Research Program of Frontier Sciences,CAS under Grant No.ZDBS-LY-JSC019;the National Natural Science Foundation of China(NSFC)under Grant Nos.11925407 and 61927901.

摘　　要：The emerging wide bandgap semiconductorβ-Ga_(2)O_(3) has attracted great interest due to its promising applications for high-power electronic devices and solar-blind ultraviolet photodetectors.Deep-level defects inβ-Ga_(2)O_(3) have been intensively studied towards improving device performance.Deep-level signatures E_(1),E_(2),and E_(3) with energy positions of 0.55–0.63,0.74–0.81,and 1.01–1.10 eV below the conduction band minimum have frequently been observed and extensively investigated,but their atomic origins are still under debate.In this work,we attempt to clarify these deep-level signatures from the comparison of theoretically predicted electron capture cross-sections of suggested candidates,Ti and Fe substituting Ga on a tetrahedral site(Ti_(GaI) and Fe_(GaI))and an octahedral site(Ti_(GaII) and Fe_(GaII)),to experimentally measured results.The first-principles approach predicted electron capture cross-sections of Ti_(GaI) and Ti_(GaII) defects are 8.56×10^(–14) and 2.97×10^(–13) cm^(2),in good agreement with the experimental values of E_(1) and E_(3) centers,respectively.We,therefore,confirmed that E_(1) and E_(3) centers are indeed associated with Ti_(GaI) and Ti_(GaII) defects,respectively.Whereas the predicted electron capture cross-sections of Fe_(Ga) defect are two orders of magnitude larger than the experimental value of the E_(2),indicating E_(2) may have other origins like C_(Ga) and Ga_(i),rather than common believed Fe_(Ga).

关 键 词：wide bandgap semiconductor defects carrier trap electron-phonon coupling first-principles calculation 

分 类 号：O471[理学—半导体物理]