Low temperature photoluminescence study of GaAs defect states*

Abstract

Low temperature (77 K) photoluminescence measurements have been performed on different GaAs substrates to evaluate the GaAs crystal quality. Several defect-related luminescence peaks have been observed, including 1.452 eV, 1.476 eV, 1.326 eV peaks deriving from 78 meV GaAs antisite defects, and 1.372 eV, 1.289 eV peaks resulting from As vacancy related defects. Changes in photoluminescence emission intensity and emission energy as a function of temperature and excitation power lead to the identification of the defect states. The luminescence mechanisms of the defect states were studied by photoluminescence spectroscopy and the growth quality of GaAs crystal was evaluated.

Atomic-scale insights of indium segregation and its suppression by GaAs insertion layer in InGaAs/AlGaAs multiple quantum wells

“…[24] 750 800 850 900 950 Figure 3(a) shows the photoluminescence (PL) spectra of the two MQWs samples with identical pumping laser power at 532 nm measured at 300 K. For the sample A, the emission peak locates at around 915 nm, accompanied with a small peak at around 871 nm which can be indexed to the peak of GaAs substrate. [25] As expected, the emission peak red shifts to 927 nm after the insertion of GaAs insertion layer in sample B. It is well known that the band gap of InGaAs is related to the In composition in the well layer.…”

Effect of Mo Vacancy on the Photoresponse of Bilayer MoS2 Film

“…This is caused by the thermal expansion of the crystal lattice in many semiconductors [12]. As the temperature decreases, defect levels can be easily identified because thermal motion is suppressed [13]. The peak located at 1,050 nm in Fig.…”