Characteristics of nanoporous InGaN/GaN multiple quantum wells

• A nanoporous InGaN/GaN multiple quantum wells has been fabricated.
• The overall external quantum efficiency for nanoporous InGaN/GaN MQWs is enhanced.
• The nanoporous structure led to more light scattering and lower defects density.

The nanoporous InGaN/GaN multiple quantum wells (MQWs) has been fabricated through rapid thermal annealing (RTA) and inductively coupled plasma (ICP) dry etching process using self-assembled Ni nanoporous masks. In comparison with the as-grown planar InGaN/GaN MQWs, both internal quantum efficiency and light extraction efficiency for nanoporous InGaN/GaN MQWs are increased, which can be concluded from the photoluminescence (PL) measurements. The thermal activation energy of nanoporous structure (107.44 meV) is significantly higher than that of the as-grown sample (33.02 meV) from temperature-dependent PL measurement, indicating that carriers are well confined and the non-radiative recombination caused by the dislocations and other defects has been reduced. Besides, enhanced light scattering in the disordered nanoporous system can further increase the output emission intensity. The enhanced performance of nanoporous InGaN/GaN MQWs reveals its promising applications for high-efficiency light-emitting devices.