Current injection emission at 333 nm from Al0.03Ga0.97N/Al0.25Ga0.75N multi quantum well ultraviolet light emitting diodes

We demonstrate ultraviolet Al0.03Ga0.97N/Al0.25Ga0.75N multi-quantum-well ( MQW) light emitting diodes (LEDs). The room-temperature electroluminescence (EL) emission was peaked at 333.0 nm under pulsed current injection. To ou r knowledge, this is the shortest wavelength yet reported for nitride QW LE Ds. As p-type layers, Mg-doped GaN/AlGaN superlattice (SL) structures were used in order to improve vertical hole conductivity. We obtained a reasonab le well width dependence on EL peak wavelength of Al0.01Ga0.99N MQW LEDs, w hich confirms that the origin of the main emission peak is from the QW regi ons. The output intensity did not saturate up to current densities approach ing 0.33 kA/cm(2). From these results, we found that the SL hole conductive layers are significantly effective for applying to light emitting devices.