Luminescence properties of hole traps in homojunction gallium nitride diodes grown by metal organic vapour phase epitaxy

A detailed investigation on p–n junction diodes of GaN using deep level transient Fourier spectroscopy (DLTFS) has been carried out. The typical deep level spectra on the various diodes on the same wafer demonstrate three electron levels labelled as E1, E2 and E3 and a hole trap H1 together with a broad band constituting three new hole levels H2, H3 and H4 therein. The electrical parameters like activation energy, trap concentration and capture cross section due to the observed levels have been measured for the comparison with the literature. The hole levels H1–H4 are found to be potentially involved in the radiative recombination and thereby, the luminescence role of the levels in the device is discussed.