In this report, the influence of magnesium doping on the characteristics of InGaN/GaN multiple quantum wells (MQWs) was investigated by means of atomic force microscopy (AFM), photoluminescence (PL), and X-ray diffraction (XRD). Five-period InGaN/GaN MQWs with different magnesium doping levels were grown by metalorganic chemical vapor deposition. The AFM measurements indicated that magnesium doping led to a smoother surface morphology. The V-defect density was observed to decrease with increasing magnesium doping concentration from ∼109 cm−2 (no doping) to ∼106 cm−2 (Cp2Mg: 0.04 sccm) and further to 0 (Cp2 Mg: 0.2 sccm). The PL measurements showed that magnesium doping resulted in stronger emission, which can be attributed to the screening of the polarization-induced band bending. XRD revealed that magnesium doping had no measurable effect on the indium composition and growth rate of the MQWs. These results suggest that magnesium doping in MQWs might improve the optical properties of GaN photonic devices.
InGaN multiple quantum wells (MQWs) V-defects metalorganic chemical vapor deposition (MOCVD) photoluminescence (PL) atomic force microscopy (AFM)
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Y. Chen, T. Takeuchi, H. Amano, I. Akasaki, N. Yamada, Y. Kaneko, and S.Y. Wang, Appl. Phys. Lett. 72, 710 (1998)CrossRefGoogle Scholar