Magnetic resonance studies of InGaN-based quantum well diodes

Photoluminescence (PL) based optically detected magnetic resonance (ODMR) s tudies as well as electroluminescence detected and electrically detected ma gnetic resonance (ELDMR and EDMR, respectively) measurements of InxGa1-xN q uantum wells were performed. In the ODMR, two PL-enhancing resonances were observed: an electron resonance and a hole resonance. The electron resonanc e is consistent with expectations for the g value in bulk InxGa1-xN for x a pproximate to 0.4 but-deviates significantly in an x approximate to 0.3 sam ple. Possible reasons for this include the effects of strain and confinemen t. The hole resonance is qualitatively similar to observations in Mg-doped GaN, but more isotropic in the x approximate to 0.3 diode than in the x app roximate to 0.4 sample. We measure relatively long radiative lifetimes (as long as similar to 0.2 ms) in the ODMR which facilitate the observation of the resonances and indicate that the electron and hole are spatially separa ted either by potential fluctuations within the quantum well or by the trap ping of the hole at an acceptor in the p layer of AlGaN whch serves as one of the confining barriers. In the EDMR and ELDMR experiments, the signal is primarily due to a reduction in the nonradiative recombination at resonanc e. While the ODMR is alwyas emission-enhancing, the ELDMR is luminescence-q uenching, supporting the notion that techniques are probing different cente rs.