Silicon delta-doping effect on photoluminescence from InGaN/GaN multi-quantum-well structures

A Si delta-doped GaN layer was included in the vicinity of five-period InGaN/GaN multi-quanturn-well structures of bluelight-emitting diodes grown on sapphire substrates by metalorganic chemical vapor deposition. An additional photoluminescence peak at 449.6mm at room temperature was observed in comparison with the case for the sample without the delta-doped layer. The radiative transition results from the energy state of the delta-doped potential below the conduction band edge. Furthermore, the delta-doped sample shows an anomalous current tunneling with a peak current of 38 mA at 5.02 V, which can be correlated with the negative acceptor-like traps of dislocation channels.