Effects of growth temperature on characteristics of Mg-delta-doped p-AlInGaN epi-layers. (October 2016)

• Record Type: Journal Article
• Authors: Wu, Zili; Zhang, Xiong; Liang, Tianhui; Feng, Zhe Chuan; Cui, Yiping
• Is Part Of: Superlattices and microstructures. Volume 98(2016)
• Page Start: 181
• Page End: 186
• Publication Date: 2016-10
• Subjects: MOCVD -- p-AlInGaN -- Mg-delta-doping -- Mg-H complex -- Hole concentration; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2016.08.025
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: The Mg-delta-doped p-AlInGaN epi-layers were successfully grown on c -plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD). The effects of growth temperature on the characteristics of the Mg-delta-doped p-AlInGaN epi-layers were investigated in detail with scanning electron microscopy (SEM), high resolution X-ray diffraction (HR-XRD), photoluminescence (PL), and Hall effect measurements. The characterization results showed that the surfaces of the p-AlInGaN epi-layers were textured with a high density of hexagonal pits, which was found to be strongly dependent on the growth temperature. This feature should be very helpful to enhance the light extraction efficiency when the p-AlInGaN epi-layers were used as the top p-contact layer for making AlInGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). In addition, the low temperature PL spectra demonstrated that the Mg-H complex-related broad emission band which was observed for the as-grown p-AlInGaN epi-layer samples was not resolvable for the annealed samples. This fact implies that the Mg-H complex can be effectively dissociated by annealing process. Moreover, owing to the improved In incorporation efficiency and crystalline quality for the p-AlInGaN epi-layers, a hole concentration as high as 1.69 × 10 17 cm −3 was achieved with the reformed Mg-delta-doping technique developed in this study. Highlights: The Mg-delta-doped p-AlInGaN epi-layers were successfully grown. A hole concentration as high as 1.69 × 10 17 cm −3 was achieved. The surface morphology was found to be dependent on the growth temperature. The Mg-H complex could be effectively dissociated by annealing process.