The emission properties of nanomaterials are influenced by the quantum confinement effect. When the size of a nanoparticle is comparable to the exciton Bohr radius, the energy levels become quantized. Smaller particles have larger energy gaps between the valence and conduction bands, leading to the emission of higher energy (shorter wavelength) light. Conversely, larger particles have smaller energy gaps and emit lower energy (longer wavelength) light.
