ABSTRACT
We present the recent results of our spectroscopic studies on optical properties of GaN grown by metalorganic chemical vapor deposition, including the issues vital to device applications such as stimulated emission and laser action, as well as carrier relaxation dynamics. By optical pumping, stimulated emission and lasing were investigated over a wide temperature range up to 420 K. Using a picosecond streak camera, free and bound exciton emission decay times were measured. In addition, the effects of pressure on the optical interband transitions and the transitions associated with impurity/defect states were studied using diamond-anvil pressure-cell technique.
