A record-long room-temperature photoluminescence (PL) lifetime (${\tau }_{\text{PL}}^{\text{RT}}$) of approximately 70 ps was obtained for the sub-bandgap 3.7 eV emission band of a 300-nm-thick c-plane Al_0.83In_0.17N epilayer for the use in cladding layers of an edge laser structure, which were grown by metalorganic vapor phase epitaxy on a low threading dislocation density nearly lattice-matched GaN substrate. The recorded ${\tau }_{\text{PL}}^{\text{RT}}$ value was twice as long as previously reported ones, indicating half concentration of nonradiative recombination centers. Room-temperature spatially resolved cathodoluminescence intensity images for the 3.7 eV band revealed nearly zero carrier diffusion length, which is consistent with the fact that ${\tau }_{\text{PL}}^{\text{RT}}$ of 70 ps is 1/35 of the near-band-edge emission of the GaN substrate (2.4 ns). As the PL decay curves for the 3.7 eV band were sufficiently fitted by the stretched exponential function, the emission likely originates from extended states such as impurities, point defects, and their complexes, as well as localized states of uneven potential profile.

中文翻译：

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通过金属有机气相外延在几乎晶格匹配的 GaN 衬底上生长的非辐射复合率降低 inc 面 Al0.83In0.17N 薄膜

创纪录的室温光致发光 (PL) 寿命 (${\tau }_{\text{PL}}^{\text{转播时间}}$) 为 300 nm 厚的c面 Al _0.83 In _0.17 N 外延层的子带隙 3.7 eV 发射带获得了大约 70 ps，用于边缘激光器结构的包覆层，该结构是通过金属有机蒸气生长的相外延在低穿透位错密度几乎晶格匹配的 GaN 衬底上。录制的${\tau }_{\text{PL}}^{\text{转播时间}}$值是先前报道的两倍，表明非辐射复合中心的一半浓度。3.7 eV 波段的室温空间分辨阴极发光强度图像显示载流子扩散长度几乎为零，这与以下事实一致${\tau }_{\text{PL}}^{\text{转播时间}}$70 ps 是 GaN 衬底的近带边缘发射 (2.4 ns) 的 1/35。由于 3.7 eV 波段的 PL 衰减曲线与拉伸指数函数充分拟合，因此发射可能源自扩展状态，例如杂质、点缺陷及其复合物，以及不均匀电位分布的局部状态。