Luminescence Of A New Material: GaN Grown On NdGaO 3

It is shown that heteroepitaxial GaN layers grown on NdGaO3, in spite of a very high conductivity (˜ 10 Ω−1cm−1) have very efficient luminescence properties. It is shown that a high electrical conductivity is caused by contamination of GaN layers with oxygen. Efficient emission due to donor bound excitons (at hv = 3.475 eV), free excitons and free electron – hole recombination have been identified. The total PL emission in the exciton region exceeds the intensity from the homoepitaxial GaN layers. It is argued that a high oxygen concentration eliminates nonradiative channels connected with point defects, leading to efficient radiative recombination.