Aluminum gallium nitride (AlGaN) nanowires have become an emerging approach for semiconductor deep ultraviolet light-emitting devices. To further improve the device performance, it is critical to understand the optical quality of AlGaN nanowires. However, today, the room-temperature internal quantum efficiency (IQE) of AlGaN nanowires is predominantly analyzed by the temperature-dependent photoluminescence (PL) approach under one excitation power or taking the PL intensity ratio at the room temperature and low temperature with different excitation powers. In both cases, one needs to assume the low temperature IQE to be 100%, which is not always valid, in particular when the excitation power changes at the low temperature. In this work, we study the room-temperature IQE of AlGaN nanowires through the detailed excitation power-dependent PL experiments and theoretical analysis. This allows us to derive the intrinsic room-temperature IQE of AlGaN nanowires as a function of the excitation power. It is found that for an Al content in the range of 22%–54%, the IQE of all samples increases as the excitation increases, followed by an efficiency droop. Moreover, comparing different samples, the IQE at low excitations increases as the Al content increases, whereas the peak IQE reduces from 73% to 56% as the Al content increases. The underlying mechanisms are also discussed in this paper.

中文翻译：

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Al含量变化的AlGaN纳米线的内在激发依赖性室温内部量子效率

氮化铝镓（AlGaN）纳米线已成为半导体深紫外发光器件的一种新兴方法。为了进一步提高器件性能，了解AlGaN纳米线的光学质量至关重要。然而，如今，主要通过一种激发功率下与温度有关的光致发光（PL）方法或采用不同激发下的室温和低温下的PL强度比，主要通过温度依赖性光致发光（PL）方法来分析AlGaN纳米线的室温内部量子效率（IQE）。权力。在这两种情况下，都需要假设低温IQE为100％，这并不总是有效的，特别是当励磁功率在低温下变化时。在这项工作中，我们通过详细的激发功率相关的PL实验和理论分析，研究了AlGaN纳米线的室温IQE。这使我们能够得出AlGaN纳米线的固有室温IQE随激发功率的变化。发现当Al含量在22％–54％范围内时，随着激发的增加，所有样品的IQE都增加，随后效率下降。此外，比较不同的样品，在低激发下的IQE随着Al含量的增加而增加，而峰值IQE随着Al含量的增加从73％降低到56％。本文还讨论了潜在的机制。随着激励的增加，所有样品的IQE都增加，随后效率下降。此外，比较不同的样品，在低激发下的IQE随着Al含量的增加而增加，而峰值IQE随着Al含量的增加从73％降低到56％。本文还讨论了潜在的机制。随着激励的增加，所有样品的IQE都增加，随后效率下降。此外，比较不同的样品，在低激发下的IQE随着Al含量的增加而增加，而峰值IQE随着Al含量的增加从73％降低到56％。本文还讨论了潜在的机制。