Emission properties of manganese-doped ZnS nanocrystals |
| |
Authors: | Sapra Sameer Prakash Ankita Ghangrekar Ajit Periasamy N Sarma D D |
| |
Institution: | Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India. sarma@sscu.iisc.ernet.in |
| |
Abstract: | We have performed steady-state and time-resolved fluorescence studies on undoped and Mn-doped ZnS nanocrystals with approximately 16 A diameter. While there is no band-edge emission, the intensity of the steady-state blue fluorescence from ZnS surface states decreases upon Mn incorporation, which gives rise to an orange emission. These results show that Mn incorporation competes very effectively with the donor-acceptor surface states for the energy transfer from the electron-hole pair excited across the band gap. In both undoped and doped samples, the time-resolved fluorescence studies establish the presence of a distribution of decay lifetimes possibly due to a number of emission centers in the nanocrystals. A faster short-time decay of the blue emission in the Mn-doped samples compared to that in the undoped sample suggests an additional decay channel for the surface states via an energy transfer from these states to the dopant levels. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|