Studies on the Material and Photoluminescence Characteristics of the Structure of Al_0.9Ga_0.1As/GaAs DBR with Varied Doping

Al_0.9Ga_0.1As/GaAs distributed Bragg reflector (DBR) structure with different doping type and doping concentrations was grown by metal organic chemical vapor deposition (MOCVD), and the material and optoelectronic characteristics were studied by X-ray diffraction (XRD) rocking curves, scanning electron microscopy (SEM), electrochemical capacitance–voltage (ECV) profiling, and low-temperature photoluminescence spectroscopy. Results showed that period thickness of AlGaAs and GaAs layers was reduced by the CCl₄ doping process and that the AlGaAs layer achieved a higher doping concentration than the GaAs materials. Additionally, there exist four recombination mechanisms in the structure of fabricated Al_0.9Ga_0.1As/GaAs DBR with varied doping. The recombination between the electrons of the conduction band and holes of the valence band in the 2.09 × 10¹⁸ cm⁻³ Si-doped GaAs layers dominated the photoluminescence in the lower temperature range, while recombination in the 1.08 × 10¹⁸ cm⁻³ C-doped GaAs layers gradually became the dominant factor at near room temperature.