Study On Photoluminescence Spectra Of ?-doped GaSb_0.93Bi_0.07/GaSb Single Quantum Well

Photoluminescence(PL)spectroscopy as a classic method for studying the luminescent characteristics of semiconductor materials,has the characteristics of non-destructive and high sensitivity.It has considerable advantages in analyzing the energy band structure of semiconductor materials,and can not only reveal the intrinsic optical process of semiconductors,but also provide information about defects and impurities in the materials.Based on a Fourier transform infrared(FTIR)spectrometer,a wide-band infrared modulated PL spectroscopic system had been realized,which takes the full advantages in significantly improving spectral resolution and signal-to-noise ratio(SNR),and hence provides effective means for the spectrum acquisition and accurate analysis of semiconductor materials.GaSbBi is considered as an important material for high-performance light-emitting devices of 2-4?m due to its narrow band gap.Similar to In Ga As/Ga As single quantum well(SQW),?doping in the well layer of GaSbBi/GaSbSQW forms a near-delta potential and confines carriers to the vicinity of the two-dimensional doped thin layer is expected to further increase its emission wavelength.Due to the possible light-emitting wavelength shift and non-uniform broadening caused by the interface structure of the GaSbBi/GaSbSQW,the relationship between the luminescent efficiency of GaSbBi SQW and the delta-doped areal density needs to be further explored.The dilute-Bi semiconductor infrared detectors reported so far are limited to single detectors.Whether it is suitable for infrared Focal Plane Array(FPA)applications has not been reported yet.Therefore,that to reveal the mechanism of the effect of delta doping on luminescent efficiency,and to characterize is the in-plane uniformity,may provide an important reference for manufacture and performance optimization of GaSbBi-based high-performance infrared light-emitting devices.This work aims at the infrared PL characteristics of the GaSbBi/GaSbSQWs with different delta-doped areal densities in the well layers by using the FTIR-PL system,the excitation power,temperature-dependent PL spectroscopy and in-plane uniformity analyses of the Ga Sb_0.93Bi_0.07/GaSbsingle quantum well with?-doped surface density in four different wells and their undoped SQW reference samples are carried out.Major results are as following in three aspects:(1)The results of Te-doped GaSbBi/GaSbSQW and undoped comparative samples under room temperature show that the electrons introduced by doping are confined in the well,which reduces their energy and PL intensity,and the band-tailing effect is extended the full width at half maximum(FWHM)of the PL peak.Too high areal doping density can also cause the influence of background impurities.The low-temperature PL spectrum test results show that the material can show a strong spectrum signal;the temperature-varying PL spectrum comparison analyzes the evolution of the characteristic peak energy,intensity,and full width at half maximum of each sample with temperature,and it is found that Te doping has a certain degree of temperature stability.Enhance the effect.(2)Variable excitation-power infrared PL analyses of the luminescenct intensity evolution of the GaSbBi/GaSbSQW and GaSbbarrier/substrate composition show that delta-doping in the well layer leads to deterioration of the interface and the quality of the lattice in the well,causing"electron loss"and"photon loss",the infrared radiation efficiency is significantly reduced,and the relative decrease is about33%-75%.(3)Spatially resolved scanning imaging PL analyses in-well?-doped GaSbBi/GaSbSQWs under low temperature show that while doping improves the thermal stability of the sample,it also introduces local defects.The research progress provides reference for the preparation and process optimization of the system materials,and provide help for the performance optimization of dilute Bi infrared light-emitting devices.