硅基半导体纳米颗粒固体薄膜的可调谐光电性质研究

Based on complex characters of Silicon based semiconductor materials, building nano devices or nano circuits with low demensional silicon based nano-materials can greatly help the microcosmicalizing and multifunctionalizing of microelectronic devices. Silicon based nanomaterials also show us a wide,potential prospect on photoelectronics and bio-electronics. In result, there appears a varies of researches which focus on silicon based nanomaterials with photoluminescence originating from quantum confinement effect. Although there are so many reports, people never succeed in fabricating silicon based nanocrystals solid films with a continuous, tunable electroluminescence in visible range, which blocks applications of Si-based semiconductor luminescent nanocrystals. Building on our previous works, in this work we will fabricate quantum Si nanocrystals with tunable photoluminescence in blue range, originating from quantum confinement effect, which never be producted before. For the next step, the influences on luminescent characters of physics and chemical environments around the Si nanocrystals will be completely analysed, which can help the researches about passivation the surfaces of nanocrystals with appropriate groups. After this part, it is highly prospective that a Si-nanocrystal solid film will be fabricated for the first time, with a continuous, tunable photoluminescence in blue-green range. The followed step is enhancing the luminescent quantum efficiencies and electronic performances of both Si nanocrystals film and SiC nanocrystals film(fabricated in our former works), and exploring the electroluminescent mechanism. With studies above all, we are probable to carry out the continuous, tunable electroluminescence of Silicon based semiconducor nanocrystals, which is never achieved before. The consequent studies on practical technology about nano-photoelectronic devices will be greatly improved base on our results.

基于硅基半导体材料优异的物理和化学性能，用低维硅基纳米材料结合半导体加工工艺构筑器件，可为Si基微纳器件和纳米电路打下基础，对电子器件微观化、多功能化有重大意义。在光电子学、生物医药方面，Si基纳米材料也展示了广阔的前景。因而具有量子限制效应的Si基半导体纳米发光材料的研究十分活跃，近年来报导了很多工作，却从未成功制备在可见光波段有连续可调谐电致发光的Si基半导体量子点固体薄膜。这一难题也阻碍了对Si基量子点发光特性的应用。在前期工作基础上我们将首次制备具有基于量子限制效应、可调谐蓝光发射的Si量子点；分析表面物理和化学环境对发光特性的影响，用原子基团钝化量子点表面，有望第一次获取蓝-绿光波段连续可调谐发光的Si量子点固体薄膜；在此基础上改善Si和SiC量子点固体薄膜的荧光效率和电学性能，探索硅基量子点固体薄膜的电致发光机理，首次实现硅基量子点固体薄膜的连续可调谐电致发光，拓展下游应用研究

出于信息产业技术发展的需求，光电子集成技术得到了迅速的推动。性能出色的材料以及器件，主要包括光发射和光探测器件，是实现光电子集成的关键。作为间接带隙材料，Si体材的光致发光是极其微弱的。但是当尺度减小到纳米量级后，激发和复合的效率将大大增加，明显的提高了发光的效率。多年来人们尝试制备了多种形貌的硅基半导体纳米材料，希望实现高效率、稳定，尤其是具有宽光谱可调谐发光的固体薄膜。然而，由于硅基半导体纳米材料结构的复杂性，报道的发光一般仅限于很窄的光谱范围，很难将硅纳米发光材料应用到技术领域。. 本项目成功实现了硅量子点基于量子限制效应在紫-蓝-绿波段强烈可调光致发光现象，并制备了具有肉眼可见的、可见光波段连续可调谐的荧光发射特性的硅纳米颗粒固体薄膜，定性分析发光起源为量子限制效应和表面局域态的共同作用。硅纳米颗粒的这种可见光波段随激发波长可调谐的特性使得它在发光器件、荧光探测等方面极具应用潜力；硅纳米颗粒表面和氢原子、羟基等的键合作用使得它在生物探测、光电子学方面，也展示了广阔的前景。另外，基于观测到的硅纳米结构和水分子的键合情况和良好的传感特性，我们测量了硅纳米柱阵列的在不同湿度下的电导特性，发现了低维硅纳米结构作为高灵敏度、兼容性强的湿敏传感器件的美好前景。额外从CdS薄膜上生长SiO2纳米柱阵列（NPA）观测到的增强光致发光让我们发现了硅基纳米结构对半导体光致发光特性的改善作用。考虑硅基纳米结构是否都有类似的性质，这一特性可有效改进硅纳米结构作为可见光波段发光器件、传感器件的特性。在制备硅纳米短柱有序阵列的过程中，我们发现了利用纳米球光刻技术制造的硅纳米点连接的纳米线的一种简易方法，这一方法制作得到的纳米结构常具有光子晶体的性质，具有独特的潜在应用，可以广泛应用在许多方面，比如制造光电器件、催化、数据存储等。