In this work, we analyze and model the effect of a constant current stress on an ultraviolet light-emitting diode with a nominal wavelength of 285 nm. By carrying out electrical, optical, spectral, and steady-state photocapacitance (SSPC) analysis during stress, we demonstrate the presence of two different degradation mechanisms. The first one occurs in the first 1000 min of stress, is ascribed to the decrease in the injection efficiency, and is modeled by considering the defect generation dynamics related to the de-hydrogenation of gallium vacancies, according to a system of three differential equations; the second one occurs after 1000 min of stress and is correlated with the generation of mid-gap defects, for which we have found evidence in the SSPC measurements. Specifically, we detected the presence of deep-level states (at 1.6 eV) and mid-gap states (at 2.15 eV), indicating that stress induces the generation of non-radiative recombination centers.

中文翻译：

---

模拟基于 AlGaN 的 UV-C LED 的退化机制：从注入效率到中间带隙状态的生成

在这项工作中，我们分析并模拟了恒流应力对标称波长为 285 nm 的紫外发光二极管的影响。通过在应力期间进行电学、光学、光谱和稳态光电容 (SSPC) 分析，我们证明了两种不同降解机制的存在。第一个发生在应力的前 1000 分钟内，归因于注入效率的降低，并且通过考虑与镓空位脱氢相关的缺陷生成动力学根据三个微分方程组进行建模；第二个发生在 1000 分钟应力之后，并且与中间间隙缺陷的产生相关，我们在 SSPC 测量中找到了证据。具体来说，我们检测到深层次状态的存在（在 1.