GaN electroluminescent devices: Preparation and studies

It is shown that the properties of GaN:Zn mainly depend on three parameters: partial pressure of zinc, additional HCl and GaCl. Therefore, it is possible reliably to obtain layers, either N-type or semi-insulating, with P-type tendency. The cathodoluminescence spectra of these layers are composed of four bands, blue, green, yellow and red, which depend on the above parameters. Using these results it has been possible to prepare electroluminescent M-i-n devices emitting over a wide spectra range (blue to yellow) with good efficiencies. The electrical and optical characteristics of these devices are analysed. An injection model is discussed.