Effects of Si doping in the barriers on the optical properties of In0.15Ga0.85N/In0.015 Ga0.985N multiple quantum wells

We studied the effects of Si doping on the optical properties of In0.15Ga0.85N/In0.015Ga0.985N multiple quantum wells (MQWs) by using photoluminescence (PL) and time-resolved PL measurements. The Si doping concentration in the In0.015Ga0.985N barriers was varied from 2 x 10(18) to 1 x 10(19) cm(-3). As the Si doping was increased, the PL showed an increase in the emission intensity and a blueshift of the peak energy. The temporal behavior of the PL was also studied. The 10-K recombination lifetime depended strongly on the Si doping level in the InGaN barriers, decreasing from similar to 80 ns to similar to 20 ns as the doping level increased from 2 x 10(18) to 1 x 10(19) cm(-3). The emission peaks shifted towards lower energy as time evolved.