Capture kinetics at deep-level electron traps in GaN-based laser diode

Two deep‐level electron traps, E1 at EC – 0.23 eV and E2 at EC – 0.55 eV, have been revealed by means of deep‐level transient spectroscopy (DLTS) in a GaN‐based laser‐diode heterostructure grown by metalorganic vapour‐phase epitaxy on a bulk GaN substrate. The two traps represent different electron capture behaviours. The E1 trap, which exhibits the logarithmic capture kinetics and the DLTS‐line shape characteristic of band‐like electron states, is attributed to the core states of threading dislocations in a p ‐type layer of the structure. In contrast, the E2 trap, being the most prominent deep‐level electron trap in GaN layers, displays the exponential capture kinetics and is assigned to isolated point defects, likely the nitrogen antisite defect. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)