Gallium Nitride Light-Emitting Diodes Grown on Silicon Substrates

Light-emitting diodes (LED) of InGaN-GaN multiple quantum wells (MQW) are grown on Si(111) substrates. The lattice mismatch between GaN and Si is accommodated by a buffer layer of ZrB$_{2}$(0001) while the thermal expansion mismatch is alleviated by a transition layer consisting of AlN, AlGaN, and GaN. The ZrB$_{2}$ buffer layer is grown at Arizona State University (ASU) and the transition layer grown at Nitronex Corporation. The MQW-LED is grown on the resulting composite substrate. The fabrication and the testing of the MQW-LED are conducted at Sandia National Laboratories. The results are compared with an identical InGaN-GaN MQW-LED grown on a conventional sapphire substrate. The three-way collaboration among ASU, Nitronex and Sandia is a project of the National Science Foundation Partnership For Innovation (NSF-PFI) program.