InGaN/GaN quantum wells with low growth temperature GaN cap layers

The use of a low growth temperature, thin (0-30 angstrom) GaN cap is investigated as a means to reduce indium desorption following the growth of InGaN quantum wells. The cap is grown at the same low temperature as the quantum well, following which the temperature is ramped up for the growth of the remainder of the barrier. Increasing the cap layer thickness results in a red shift of the emission, consistent with decreased indium loss, and a decrease in the room temperature optical efficiency, attributed to the formation of defects in the GaN cap. (c) 2007 Elsevier B.V. All rights reserved.