Departamento de Física, CCE, Universidade Federal de Viçosa, 36570-900 Viçosa, Minas Gerais, Brazil.
Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, 36301-160 São João del-Rei, Minas Gerais, Brazil.
J Chem Phys. 2017 Oct 21;147(15):154102. doi: 10.1063/1.4999093.
A new analytical expression for the size-dependent bandgap of colloidal semiconductor nanocrystals is proposed within the framework of the finite-depth square-well effective mass approximation in order to provide a quantitative description of the quantum confinement effect. This allows one to convert optical spectroscopic data (photoluminescence spectrum and absorbance edge) into accurate estimates for the particle size distributions of colloidal systems even if the traditional effective mass model is expected to fail, which occurs typically for very small particles belonging to the so-called strong confinement limit. By applying the reported theoretical methodologies to CdTe nanocrystals synthesized through wet chemical routes, size distributions are inferred and compared directly to those obtained from atomic force microscopy and transmission electron microscopy. This analysis can be used as a complementary tool for the characterization of nanocrystal samples of many other systems such as the II-VI and III-V semiconductor materials.
提出了一种新的分析表达式，用于胶体半导体纳米晶体的尺寸相关能隙，该表达式是在有限深度方阱有效质量近似的框架内提出的，以便对量子限制效应进行定量描述。这使得人们可以将光学光谱数据（光致发光光谱和吸收边）转换为胶体系统的准确粒径分布估计值，即使传统的有效质量模型预计会失效，这种情况通常发生在属于所谓的强限制限域的非常小的粒子中。通过将报道的理论方法应用于通过湿化学途径合成的 CdTe 纳米晶体，推断出尺寸分布，并直接与原子力显微镜和透射电子显微镜获得的尺寸分布进行比较。这种分析可作为许多其他系统（如 II-VI 和 III-V 半导体材料）的纳米晶体样品的表征的补充工具。
