Undoped and Si-doped AlGaN/AlN multiple quantum wells （MQWs） were grown on A1N/Sapphire templates by metalorganic phase vapor epitaxy. High-resolution x-ray diffraction measurements showed the high interface quality of the MQWs little affected by Si-doping. Room-temperature （RT） cathodoluminescence measurements demonstrated a significant enhancement of the RT deep ultraviolet emission at about 240 nm from the AlGaN/AlN MQWs by Si doping. The mechanism of the improved emission efficiency was that the Si-doping partially screens the internal electric field and thus leads to the increase of the overlap between electron and hole wavefunctions. Further theoretical simulation also supports the above results.
