摘要:
本文通过对含有高In组分量子点的双波长LED进行了模拟计算,并对器件的能带结构、载流子浓度、复合速率和辐射光谱进行了研究.通过对器件结构的调整与对比,发现蓝绿双波长LED的绿光量子阱中加入高In组分量子点后可以拓宽辐射光谱,使LED光谱具有更高的显色指数,为实现无荧光粉的白光LED提供指导.量子点对载流子具有很强的束缚能力,并且载流子在量子点处具有更短的寿命,载流子优先在量子点处复合,量子点处所对应的黄光与量子阱润湿层所对应的绿光的比例随量子点浓度的增大而增大,载流子浓度较低时以量子点处的黄光辐射为主,载流子浓度变大后,量子点复合逐渐达到饱和,绿光辐射开始占据主导.对间隔层厚度和间隔层掺杂浓度的调节可以很方便地调控载流子的分布,从而实现对含有量子点的双波长LED两个活性层辐射速率的调控.结果表明,通过对量子点浓度、间隔层厚度、间隔层掺杂浓度的控节可以很好地实现对LED辐射光谱的调控作用.
Abstract:
A theoretical simulation of electrical and optical characteristics of GaN-based dual-wavelength light-emitting diodes (LED) with high In content in the quantum dots (QDs) which are planted in quantum wells is conducted with APSYS software. The adjustment and contrast of the structure of the devices showed that the blue and green dual-wavelength LEDs will have a broader radiation spectrum and a higher color rendering index when QDs are planted in the green quantum wells. QDs have strong blinding capacity with the carriers, and the carriers at the QDs have shorter lifetime than they are in the wetting layers, so the carrier recombination will give preference to the QDs. It is shown that the distribution of the carriers could be easily controlled by adjusting the spacing layer thickness and the spacing layer doping concentration, so as to control the radiation rate of the two active layers of the dual-wavelength LEDs. Therefore, the spectrum-control of the dual-wavelength LED with QDs planted in QWs could be realized by adjusting the concentration of quantum dots, the thickness of the spacing layer and the doping concentration in the spacing layer. This article can provide guidance for the realization of the non-phosphor white LED.
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