Abstract This work suggests new alternative explanation why a single InGaN quantum well (QW) or the deepest QWs in the multiple quantum well (MQW) structures suffer with a high non-radiative recombination rate. According to SIMS results, positron annihilation spectroscopy and photoluminescence measurements we suggest that vacancy of Ga in complex with hydrogen atoms can play a dominant role in non-radiative Shockley-Read-Hall recombination of the deepest QWs in InGaN/GaN MQW structures. Vacancy of gallium originate dominantly in GaN buffer layers grown at higher temperatures in H2 atmosphere and are transported to the InGaN/GaN MQW region by diffusion, where they are very effectively trapped in InGaN layers and form complex defects with hydrogen atoms during epitaxy of InGaN layers. Trapping of gallium vacancies is another suggested mechanism explaining why the widely used In containing prelayers help to increase the luminescence efficiency of the InGaN/GaN MQW active region grown above them. Understanding the mechanism why the luminescence efficiency is suppressed in deeper QWs may be very important for LED community and can help to develop new improved technologies for the growth of InGaN/GaN MQW active region.

中文翻译：

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InGaN/GaN 多量子阱结构最深 QW 中的秘密发光杀手

摘要 这项工作提出了新的替代解释，为什么单个 InGaN 量子阱 (QW) 或多量子阱 (MQW) 结构中最深的 QW 具有高非辐射复合率。根据 SIMS 结果、正电子湮没光谱和光致发光测量，我们表明与氢原子复合的 Ga 空位可以在 InGaN/GaN MQW 结构中最深 QW 的非辐射 Shockley-Read-Hall 复合中起主导作用。镓的空位主要来源于在 H2 气氛中在较高温度下生长的 GaN 缓冲层，并通过扩散传输到 InGaN/GaN MQW 区域，在那里它们非常有效地被困在 InGaN 层中，并在 InGaN 层的外延过程中与氢原子形成复杂的缺陷. 捕获镓空位是另一种建议机制，可以解释为什么广泛使用的含 In 预层有助于提高在其上方生长的 InGaN/GaN MQW 有源区的发光效率。了解为什么在更深的 QW 中抑制发光效率的机制对于 LED 社区可能非常重要，并且可以帮助开发用于 InGaN/GaN MQW 有源区生长的新改进技术。