A direct epitaxial approach to achieving ultrasmall and ultrabright InGaN micro light-emitting diodes (μLEDs) has been developed, leading to the demonstration of ultrasmall, ultraefficient, and ultracompact green μLEDs with a dimension of 3.6 μm and an interpitch of 2 μm. The approach does not involve any dry-etching processes which are exclusively used by any current μLED fabrication approaches. As a result, our approach has entirely eliminated any damage induced during the dry-etching processes. Our green μLED array chips exhibit a record external quantum efficiency (EQE) of 6% at ∼515 nm in the green spectral region, although our measurements have been performed on bare chips which do not have any coating, passivation, epoxy, or reflector, which are generally used for standard LED packaging in order to enhance extraction efficiency. A high luminance of >107 cd/m2 has been obtained on the μLED array bare chips. Temperature-dependent measurements show that our μLED array structure exhibits an internal quantum efficiency (IQE) of 28%. It is worth highlighting that our epitaxial approach is fully compatible with any existing microdisplay fabrication techniques.

中文翻译：

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实现超小和超亮InGaN微型发光二极管（μLED）的直接外延方法。

已经开发出一种直接外延方法来实现超小且超亮的InGaN微发光二极管（μLED），从而展示了尺寸为3.6μm，间距为2μm的超小型，超高效和超紧凑型绿色μLED。该方法不涉及任何现有的μLED制造方法专用的任何干法蚀刻工艺。结果，我们的方法完全消除了干蚀刻过程中引起的任何损坏。尽管我们的测量是在没有任何涂层，钝化，环氧树脂或反射器的裸露芯片上进行的，但我们的绿色μLED阵列芯片在约515 nm处的绿色光谱区域内的外部量子效率（EQE）达到了创纪录的6％。通常用于标准LED封装，以提高提取效率。在μLED阵列裸芯片上获得了大于107 cd / m2的高亮度。与温度有关的测量表明，我们的μLED阵列结构具有28％的内部量子效率（IQE）。值得强调的是，我们的外延方法与任何现有的微显示器制造技术完全兼容。