Influence of Si doping on optical properties of wurtziteGaN

Abstract

The band gap shift (BGS) of Si-doped wurtzite GaN for impurityconcentrations spanning the insulating to the metallic regimes has beeninvestigated at low temperature. The critical impurity concentration forthe metal-non-metal transition is estimated from the generalized Drudeapproach for the resistivity to be about 1.0×1018 cm-3.The calculations for the BGS were carried out within a framework of therandom phase approximation, taking into account the electron-electron,electron-optical phonon, and electron-ion interactions. In the wake ofvery recent photoluminescence measurements, we have shown and discussed thepossible transitions involved in the experimental results.