Parasitic p–n junctions formed at V-pit defects in p-GaN

The luminescent and recombination properties of V-pit defects in p-GaN(Mg) grown by metalorganic chemical vapor deposition (MOCVD) were studied scanning electron microscopy (SEM) the secondary electron, cathodoluminescence (CL), beam induced current (EBIC) modes, combined with CL spectra measurements EBIC collection efficiency measurements. Similar studies performed on low-dislocation-density freestanding n-GaN crystals. For MOCVD p-GaN films, SEM investigations supplemented capacitance–voltage, current–voltage, deep level transient spectroscopy analysis Ni Schottky diode, Ohmic contacts. These experiments show that V-pits increase leakage diodes, as films imaging results suggest region V-pits, a parasitic p–n junction is formed. We also observe that, contribution 3.2 eV defect band strongly enhanced compared to 3 blue dominates spectra.