源自纳米半导体的高效率硅基电致发光

国际上，源自纳米硅的电致发光外量子效率长期处于低迷状态。2011年美国明尼苏达大学的Holmes研究组实现了源自纳米硅的效率高达8.6 %的电致发光。本基金申请拟借鉴该项研究成果，结合我们研究组近二十年来研究硅基电致发光的经验，加以系统研究，发展出源自纳米硅的硅基高效率电致发光，即将他们的ITO基改为硅基。为了保证源自纳米硅的硅基电致发光具有高效率，选择参数优化的硅片或微晶硅薄膜为阳极，并对阴极和发光结构中其它各层作相应的调整。还拟将发光源自纳米硅颗粒的高效率电致发光推广到发光分别源自纳米硅，纳米锗和纳米PbS颗粒等三种情况的高效率电致发光。通过改变纳米锗和纳米PbS颗粒的尺寸，使电致发光波长达到1.3和1.55微米波段。

Holmes' group of university of Minnesota in United States demonstrated highly efficient electroluminescene originated from silicon nanoparticles with external quantum efficiencies of up to 8.6% in 2011. We apply this fund to systematically research and develop silicon based highly efficient electroluminescene originated from nanoscale semiconductors by using Holmes et al's results for reference and combining the experiences of silicon based electroluminescene in our research group in the last 20 years. On the premise of ensuring high efficiencies, we plan to change the Holmes et al's ITO based devices to silicon based devices, which means to employ bulk silicon or thin microcrystalline silicon film as the anodes of devices. The bandgap of silicon is 1.12 eV. The wavelength of electroluminescene is below 1.1 if silicon nanoparticles are used. To extend the range of the wavelength of electroluminescene, especially the wavelength of 1.55 which is the lowest loss wavelength for optical communications, we plan to extend the electroluminescene from silicon nanoparticles to the electroluminescene from Ge and PbS nanoparticles. Ge and PbS are indirect and direct bandgap semiconductors, whose bulk materials bandgaps are 0.67eV and 0.41eV, respectively. The wavelength of electroluminescene can be increased up to 1.85 and 3.0 , which include 1.3 and 1.55 band. According to quantum confinement effect, the wavelengths of electroluminescene originated from these three kinds of nanoparticles can be continuously tuned from near ultraviolet to 3 micron infrared as the sizes of Si, Ge and PbS nanoparticles are changed.