Photoluminescence of Doped GaN Films

GaN, its allows, QWs and MQWs have gained an important place among shortwavelength optical emitters and high temperature electronic devices. A major obstacle for the realisation of such devices from Metal-Organic Vapour Phase Epitaxy (MOVPE) grow GaN film is an apparent difficulty to achieve p-type material due to highly n-type residual conductivity. Several groups reported their ability to dope GaN using Mg as a dopant, in nitrogen environment to active Mg dopants. A strong blue emission is present when GaN films are heavily doped with Mg.

Controlled n-type conductivity can be obtained using Si as dopant. It is now that Si replaces Ga in the lattice and acts as a single donor. Besides the near-band-gap emission centred at 3.461 eV, which becomes broader with increasing Si concentration also transitions at lower energies are observed.

In the present work we analyze these emissions by time-resolved spectroscopy and steady-state spectroscopy.