Optimization of Nanoscale Phenomena in AlGaN for Improved UV Emitters

摘要

We have developed AlGaN films deposited by plasma assisted molecular beam epitaxy (PA-MBE) that can possess enhanced internal quantum efficiency ( > 30%) due to the presence of nanometer scale compositional inhomogeneities (NCI-AlGaN) within a wider bandgap matrix that inhibit nonradiative recombination through the large defect densities ( > 10~(10)cm~(-2)) in these materials. Time- and temperature-dependent studies of the UV photoluminescence from these NCI AlGaN films as a function of growth conditions have been performed with the goal of optimizing the emission efficiency. Measurements of radiative and nonradiative lifetimes in conjunction with modeling indicate that the NCI AlGaN inherently combines inhibition of nonradiative recombination with reduction of radiative lifetime, providing a potentially higher efficiency UV emitter active region.