Time-resolved photoluminescence properties of hybrids based on inorganic AlGaN/GaN quantum wells and colloidal ZnO nanocrystals

• We studied the exciton dynamics in AlGaN/GaN/ZnO hybrid structures.
• Resonant energy transfer was observed if acceptor–donor distance is 3 nm.
• Optimum efficiency of the resonant energy transfer was observed at 60 K (∼42%).

Dynamic properties are studied for the AlGaN/GaN quantum well (QW) structures with and without the coating of colloidal ZnO nanocrystals (NCs). The QW exciton recombination rate was reduced in such hybrids compared to the bare QW structure only in the sample with the thinnest cap layer of 3 nm. Assuming that one of the recombination mechanisms in this hybrid is non-radiative resonant energy transfer (NRET) between the QW and the energy acceptor material i.e. ZnO NCs, the maximum pumping efficiency was estimated to be ∼42% at 60 K. The NRET effect is, however, vanished after several months despite that the hybrid structures are composed of chemically stable components.