Review of luminescence properties of semiconductor nanocrystals

This paper reviews recent advances in luminescence properties of semiconductor nanocrystals. The onset of absorption takes place at longer wavelength with reducing the size of the semiconductor nanocrystals. Such blueshift with reducing size of the nanocrystals is the reflection of bandgap increase owing to the quantum confinement effect. In most cases blueshift in the peak of photoluminescence (PL) spectra is observed with reducing size of the nanocrystals, but the luminescence from certain surface states may give rise to the red-shift with reducing size of the nanocrystals. Whereas the decay time of luminescence decreases, the quantum efficiency of luminescence and Stokes shift increase with reducing size of the nanoparticles. The photoluminescence intensity of nanocrystals decreases with increasing temperature. It is optimum for a particular concentration of the dopants in the nanoparticles. The luminescence of semiconductor nanoparticles is exciting to the researchers and it has several important potentials