Increased power from deep ultraviolet LEDs via precursor selection

Deep ultraviolet AlGaN multiple quantum wells as well as single Al_0.5 Ga_0.5 N layers were grown at varying growth rates using both trimethylgallium (TMGa) and triethylgallium (TEGa) as precursors. The incorporation efficiency of the two precursors was compared, as well as the impurity concentrations measured by secondary ion mass spectroscopy (SIMS). The electronic transport properties of each were examined. Photoluminescence of quantum wells was also performed, with an efficiency increase with decreasing growth rate observed for quantum wells grown with TMGa. Wells grown using TEGa, although significantly more efficient at high growth rates than those using TMGa, showed no variation in intensity across growth rates and were surpassed in light output by TMGa quantum wells grown at a sufficiently slow rate. LEDs were grown using both precursors, resulting in a four-fold increase in measured brightness over previously reported results from this university.