物理学报2024，Vol.73Issue(2)：287-292,6.DOI:10.7498/aps.73.20231339
In0.52Al0.48As/InP的正向和反向异质结在带隙附近的不同光谱现象
Different spectral features near the energy bandgaps of normal and inverse heterostructures of In0.52Al0.48As/InP
摘要
Abstract
Photoconductivity(PC)spectroscopy and photoluminescence(PL)spectroscopy were used to characterize two heterostructure configurations of InAlAs/InP grown by molecular beam epitaxy(MBE)on the InP(100)substrate.The sample A is the type called normal heterostructure,which has an In0.52Al0.48As layer grown on InP,while sample B is called the inverse type formed by an InP cap layer on In0.52Al0.48As.The front excitation was employed in both PC experiment and PL experiment and the measurements were conducted at 77 K.The PC spectrum of sample A shows an abnormal step-like drop when the photon energy is larger than the energy band gap of In0.52Al0.48As.The phenomenon implies that the conductance of sample is a multilayer effect including the contribution of interfacial two-dimensional electron gas(2DEG).Moreover,a conductance peak is observed at 916 nm below the bandgap of InP.Accordingly,an intense luminescent peak at the wavelength manifests in the PL spectrum.The origin of the 916 nm peak is attributed to the recombination of 2DEG electrons with the valence band holes excited near the interface.However,the spectral feature of the above energy does not exist in both PC and PL spectra of sample B.This difference may be explained by the different interface electronic structures of the inverse interface.For the latter case,considering that a graded variation in In-As-P composition is related to the inverse interface of InP/InAlAs,the band bending effect should be weak.In such a case,the bound energy of 2DEG in the interface potential well is raised closer to the conductance band of the bulk.Consequently,the recombination energy of 2DEG at the inverse interface with the holes in the valence band is close to the band-to-band transition of InP bulk and the luminescence is difficult to be distinguished from that of bulk InP.The work also demonstrates that the comparative study with both PC technique and PL technique is helpful to provide a full insight into the interface electronic property.关键词
半导体光谱/半导体界面/光电导/光致发光Key words
semiconductor spectroscopy/semiconductor interface/photoconductance/photoluminescence引用本文复制引用
吴洋,胡晓,刘博文,顾溢,查访星..In0.52Al0.48As/InP的正向和反向异质结在带隙附近的不同光谱现象[J].物理学报,2024,73(2):287-292,6.基金项目
国家自然科学基金(批准号:61874069)资助的课题. Project supported by the National Natural Science Foundation of China(Grant No.61874069). （批准号:61874069）
