The luminescent and recombination properties of V-pit defects in p-GaN(Mg) grown by metalorganic chemical vapor deposition (MOCVD) were studied by scanning electron microscopy (SEM) in the secondary electron, cathodoluminescence (CL), and electron beam induced current (EBIC) modes, combined with CL spectra measurements and EBIC collection efficiency measurements. Similar studies were performed on low-dislocation-density freestanding n-GaN crystals. For MOCVD p-GaN films, the SEM investigations were supplemented by capacitance-voltage, current-voltage, deep level transient spectroscopy analysis with Ni Schottky diode, and Ohmic contacts. These experiments show that V-pits in p-GaN increase the leakage current of Schottky diodes, as in n-GaN films and crystals. EBIC imaging and EBIC collection efficiency results suggest that in the region of V-pits, a parasitic p-n junction is formed. We also observe that, in V-pits, the CL spectra the contribution of the 3.2 eV defect band is strongly enhanced compared to the 3 eV blue CL band that dominates the spectra.
Bibliographical noteFunding Information:
The work at NUST MISiS was financially supported by the Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISiS” (No. К2-2020-040). The work at IMT RAS was supported in part by the State Task No 075-00355-21-00. The work at Korea University was supported by the Technology Innovation Program (No. 20004479, Micro LED chip and module fabrication technology with integrated field effect transistor for IoT application) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea). The work at UF was sponsored by NSF DMR (No. 1856662 (James Edgar)].
© 2021 Author(s).
ASJC Scopus subject areas
- General Physics and Astronomy