采用高温微乳液的化学方法,在溶液中合成了高产率的CdSe四脚状纳米晶粒。高分辨透射电镜(HRTEM)分析结果表明,CdSe四脚状纳米晶粒是由1个立方的核心和4个六方的臂所组成。研究了该四脚晶粒的变激发功率光荧光(PL)谱和变温的PL谱,分析发现低温时四脚晶粒的光荧光主要来自于被表面缺陷所局域的激子的辐射复合,而随着温度升高,束缚激子被热激发,室温时光荧光主要来自于自由激子的贡献。CdSe纳米量子点的退局域化温度比四脚纳米晶粒的高,而12K时CdSe纳米量子点的局域化能量比四脚纳米晶粒的也大得多,并对这一现象作了解释。
High yield CdSe nano-tetrapods were synthesized in solution by using the chemical method of high-temperature microemulsion.High resolution transmission electron microscopy(HRTEM) result shows that one CdSe nano-tetrapod is formed with one cubic core and four he-xagonal arms.The excitation power-and temperature-dependent photoluminescence(PL) spectra for the CdSe nano-tetrapods were studied,respectively.It is found that the PL of the tetrapods are mainly from the combination of the excitons localized by the surface defects at low temperature.While as the temperature increases,the bound excitons are thermalized.The PL mainly comes from the contribution of free excitons at room temperature.The delocalized temperature of the CdSe nano quantum dots is higher than that of the nano-tetrapods,and the localization energy of the CdSe nano quantum dots is much larger than that of the nano-tetrapods.The possible reason was explained.