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GaAs/In$_{0.1}$Ga$_{0.9}$As/GaAs 이종접합 구조에서 InGaAs 층의 두께에 따른 광 특성을 photoreflectance (PR) 방법으로 조사하였다. 그리고 상온 PR 스펙트럼에서 GaAs의 밴드갭에 관련된 신호가 약 1.42 eV에서 관측되었으며, 그리고 In$_{0.1}$Ga$_{0.9}$As에 관계된 신호는 두께 70, 150 및 300 nm에 대해서 각각 1.311, 1.296 및 1.287 eV에서 관측되었다. 상온 및 저온에서 Franz-Keldysh oscillations (FKOs)이 In$_{0.1}$Ga$_{0.9}$As와 GaAs 밴드갭 에너지 사이에서 관측되었으며, FKO의 주기를 통해 In$_{0.1}$Ga$_{0.9}$As/GaAs의 계면 전기장 값을 구하였다.


We have studied the photoreflectance (PR) of GaAs/In$_{0.1}$Ga$_{0.9}$As/GaAs heterostructures with different thicknesses of InGaAs layers grown by using metal-organic chemical-vapor deposition (MOCVD). The room-temperature PR spectra show two typical signals, around 1.42 and 1.30 eV, which can be attributed to the band gap energies of GaAs and InGaAs, respectively. In addition, we observe Franz-Keldysh oscillations above the InGaAs fundamental band gap. From these oscillations, we calculate the electric fields at the In$_{0.1}$Ga$_{0.9}$As/GaAs interface. Also, the temperature dependence of the PR peak is investigated.


We have studied the photoreflectance (PR) of GaAs/In$_{0.1}$Ga$_{0.9}$As/GaAs heterostructures with different thicknesses of InGaAs layers grown by using metal-organic chemical-vapor deposition (MOCVD). The room-temperature PR spectra show two typical signals, around 1.42 and 1.30 eV, which can be attributed to the band gap energies of GaAs and InGaAs, respectively. In addition, we observe Franz-Keldysh oscillations above the InGaAs fundamental band gap. From these oscillations, we calculate the electric fields at the In$_{0.1}$Ga$_{0.9}$As/GaAs interface. Also, the temperature dependence of the PR peak is investigated.