Optical properties of ZnO phosphors activated with Mn and Se impurity

Abstract

Various optical parameters of interest have been obtained from the synthesized singly and doubly doped ZnO semiconductor phosphors with variable concentrations of manganese and selenium. Time resolved photoluminescence (PL) spectra have been observed in doped phospors when these are excited by the UV laser radiation, giving rise to emission in the visible region. The phosphors under investigations were exited by UV pulsed N2 laser (having high peak output power) at room temperature. In present context transition probability, oscillator strength, integrated cross-section and dipole-moment values have been calculated from the laser induced photoluminescence decay curves of the singly and doubly doped ZnO phosphors. In case of doubly doped ZnO phosphors the increasing trend of all the parameters is attributed to the fact that the emission from shallow trapping stales plays the dominant role or it may be due to energy transfer mechanism.