光学学报, 2005, 25 (5): 683, 网络出版: 2006-05-22
CdSeS量子点的光吸收谱亚结构和光致发光激发谱分析
Photoluminescence Excitation Spectra and Absorption Spectra Analysis of CdSeS Quantum Dots
光谱学 量子点 吸收谱亚结构 光致发光激发谱 spectroscopy quantum dots absorption spectrum sub-structure photoluminescence excitation spectrum
摘要
用光致发光激发(PLE)谱分析吸收谱的亚结构。实验样品是共熔法制备的CdSeS量子点玻璃,量子点的生长时间分别为2 h和4 h,高分辨透射电子显微镜(HRTEM)分析得到样品中量子点的平均直径分别为3.6 nm和3.8 nm。在室温下对样品进行了光吸收谱和光致发光激发谱研究。光吸收谱显示了量子尺寸效应,光致发光激发谱中低能端有两个明显的峰。考虑价带简并以及电子与空穴之间的相互作用,通过理论分析和数值计算,得到1S3/2-1Se和2S3/2-1Se的跃迁能量及其随量子点半径的变化,由此确认光致发光激发谱中的两个峰分别为1S3/2-1Se和2S3/2-1Se跃迁。
Abstract
The sub-structure in absorption spectrum was analyzed by means of photoluminescence excitation (PLE) spectra. The glass samples of CdSeS quantum dots were prepared by co-melting and analyzed by means of high resolution transmission electron microscopy (HRTEM), the annealing time was 2 h and 4 h respectively, the quantum dots' diameter was 3.6 and 3.8 nm respectively. Absorption spectra and photoluminescence excitation spectra were measured at room temperature. The absorption spectra showed quantum size-dependent effects. Two peaks were observed in photoluminescence excitation spectra. The valence band degeneracy and the interaction between electrons and holes were taken into account, the energies of 1S3/2-1Se and 2S3/2-1Se transitions versus quantum dots' radii were obtained by theoretical analysis and numerical calculation. The two peaks in photoluminescence excitation spectra are assigned to 1S3/2-1Se and 2S3/2-1Se transitions, respectively.
刘炳灿, 田强, 吴正龙. CdSeS量子点的光吸收谱亚结构和光致发光激发谱分析[J]. 光学学报, 2005, 25(5): 683. 刘炳灿, 田强, 吴正龙. Photoluminescence Excitation Spectra and Absorption Spectra Analysis of CdSeS Quantum Dots[J]. Acta Optica Sinica, 2005, 25(5): 683.