Enhanced Radiative Efficiency in Blue (In,Ga)N Multiple-Quantum-Well Light-Emitting Diodes with an Electron Reservoir Layer

Temperature dependence of the EL spectral intensity is investigated between 20 and 300 K of a particularly designed blue (In,Ga)N/GaN multiple-quantum-well (MQW) light-emitting-diode (LED), which contains an additionally n-doped (In,Ga)N electron reservoir layer. The MQW-LED consists of In0.3Ga0.7N MQW layers with a nominal well width of 2.5 nm separated by 6.5 nm GaN barrier layers, prepared by metal-organic vapor-phase epitaxy with and without an n-doped In0.18Ga0.82N electron reservoir layer in order to exploit the effects of such additional layer on the carrier capture rates. It is found that by adding the electron reservoir layer, the EL spectral intensity is significantly enhanced over the wide temperature range for a fixed injection current level. These results indicate importance of the electron capture processes by radiative recombination centers in the InGaN MQW. PACS : 73.50.Gr, 78.60.Fi, 78.67.De