Dependence of internal quantum efficiency on doping region and Si concentration in Al-rich AlGaN quantum wells

The internal quantum efficiency (IQE) of Si-doped AlGaN quantum wells has been studied by means of photoluminescence spectroscopy. Analysis of the IQE as a function of doping region revealed that the IQE increased from 19% to 40% with doping of the well layers. This increase was attributed to an improvement in the interface quality between well and barrier layers as well as a reduction in point defect density. Moreover, the IQE increased to a maximum of 50% and then decreased with increasing Si concentration of the well layers. This indicated the existence of an optimum Si concentration for IQE improvement. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739431]