Description
Semiconductor nanocrystals exhibit unique optical properties arising from the quantum confinement of charge carriers. As the nanocrystal size decreases, the spatial confinement of excitons produces a pronounced blue-shift in the optical bandgap and enables wide spectral tunability. In this regime, the electronic energy levels become discretized, leading to well-defined absorption features in the optical spectra of semiconductor nanocrystals. The strength of quantum confinement increases with decreasing nanocrystal size, resulting in larger spectral separations between successive absorption peaks. This behavior is parallel to the energy level spacing in a particle confined within a finite potential well described by the Schrödinger equation, where the separation between quantized energy states depends on the width of the potential well. Meanwhile, optical studies of quantum dots provide an important platform for probing and understanding the Schrödinger wave function in confined quantum systems, since the observed spectral features directly reflect the quantized electronic states and their wave functions. Consequently, semiconductor nanocrystals serve as a tunable model system for investigating size-dependent quantum phenomena and hold significant promise for applications in optoelectronics, photovoltaics, and quantum photonic technologies.