ZnO and Zn1-xMnxO Minicrystal by CVT and Temporal Process of Photoelectrons

The ZnO and Zn1-xMnxO minicrystal were synthesized by chemical vapor transport (CVT). The electron trap structure (donor level) and process on the temporal behavior of photoelectrons of materials were respectively studied by thermo-luminescence and microwave absorption dielectric spectrometry. There are two peaks in the thermo-luminescence spectra in pure ZnO, one is -183 ℃ and the other is -127 ℃, which shows two kinds of electron trap energy level produced by the intrinsic defects in ZnO;but obtain very low thermo-luminescence that only equals to ten percent of pure ZnO in Zn1-xMnxO, which shows that its intensity of electron trap is less. The studies of microwave absorption dielectric spectrometry show that conduction band photoelectrons are two-step exponential decay process in ZnO, the lifetime of rapid process is 83 ns, while slow process is 828 ns, the reason of delay is relaxation effects of electron trap to conduction band photoelectrons. The intensity of electron trap is less in Zn1-xMnxO minicrystal, the relaxation effects of conduction band photoelectrons from electron trap is little, so electrons disappeared quickly at conduction band, and the decay process of photoelectrons is only 10～20 ns.