Light-emitting diodes (LEDs) in the wavelength region of 535-570 nm are still inefficient, which is known as the "green gap" problem. Light in this range causes maximum luminous sensation in the human eye and is therefore advantageous for many potential uses. Here, we demonstrate a high-brightness InGaN LED with a normal voltage in the "green gap" range based on hybrid multi-quantum wells (MQWs). A yellow-green LED device is successfully fabricated and has a dominant wavelength, light output power, luminous efficiency and forward voltage of 560 nm, 2.14 mW, 19.58 lm/W and 3.39 V, respectively. To investigate the light emitting mechanism, a comparative analysis of the hybrid MQW LED and a conventional LED is conducted. The results show a 2.4-fold enhancement of the 540-nm light output power at a 20-mA injection current by the new structure due to the stronger localization effect, and such enhancement becomes larger at longer wavelengths. Our experimental data suggest that the hybrid MQW structure can effectively push the efficient InGaN LED emission toward longer wavelengths, connecting to the lower limit of the AlGaInP LEDs' spectral range, thus enabling completion of the LED product line covering the entire visible spectrum with sufficient luminous efficacy.

中文翻译：

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在“绿色间隙”范围内实现高发光效率的InGaN发光二极管。

在535-570 nm波长范围内的发光二极管（LED）仍然效率低下，这被称为“绿色间隙”问题。该范围内的光在人眼中引起最大的发光感觉，因此对于许多潜在用途是有利的。在这里，我们演示了一种基于混合多量子阱（MQWs）且正常电压在“绿色间隙”范围内的高亮度InGaN LED。黄绿色LED器件已成功制造，其主要波长，光输出功率，发光效率和正向电压分别为560 nm，2.14 mW，19.58 lm / W和3.39V。为了研究发光机理，对混合式MQW LED和常规LED进行了比较分析。结果显示2。通过新的结构，由于具有更强的定位效果，在20 mA注入电流下，540 nm光输出功率提高了4倍，并且这种增强在更长的波长下变得更大。我们的实验数据表明，混合MQW结构可以有效地将有效的InGaN LED发射推向更长的波长，并连接到AlGaInP LED光谱范围的下限，从而使LED产品线能够完成覆盖整个可见光谱且具有足够发光的产品线。功效。