Abstract:
Some radiative and electric properties of heterostructures based on semiconductor nitrides emitting in the visible and UV regions are considered. The following anomalous properties of UV-emitting heterostructures are studied: the low-temperature emission quenching, a strong non-ideality of I–V curves, and the increase in the slope of these characteristics upon cooling. The anomalous emission quenching is especially typical for ~3-nm thick single-quantum-well structures, but it is absent in a 50-nm thick double heterostructure. It seems that this difference is caused by the fact that the capture of carriers at the levels in quantum wells slows down upon cooling, and a 'through' injection of carriers occurs into the opposite emitter layer. In addition, electrons injected into the p region reduce its resistance. The consideration of the injection-induced conductivity in the passive layer allows us to explain satisfactorily the electric anomalies.