|
|||||
|
|
Photoluminescence study of Ge nanocrystals irradiated by reactor neutron flux |
|
| Authors: | Shaobo Dun Qiang Hu Caofeng You Bin Tang Ningkang Huang |
| Affiliation: | a Department of Physics and Key Laboratory for Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064, PR China b International Center for Material Physics, Chinese Academy of Sciences, Shenyang 110015, PR China c Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Sichuan Mianyang 621900, PR China d Institute of Nuclear Science and Technology and Key Laboratory for Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064, PR China |
| Abstract: | Samples of Ge nanocrystals (Ge-ncs) embedded in amorphous SiO2 film were prepared by Ge ion implantation and subsequent primary thermal annealing. These samples were irradiated by neutron flux in a nuclear reactor followed by the second annealing. Irradiation with thermal neutrons leads to doping of nanocrystals with Ga, As and Se impurities due to nuclear transmutation of isotope 70Ge into 71Ga, isotope 74Ge into 75As, isotope 76Ge into 77Se, respectively (neutron transmutation doping, NTD). Irradiation with fast neutrons leads to appearance of radiation damages, which are expected to be removed after the second annealing. Photoluminescence (PL) measurements show that PL is quenched after neutron irradiation, and restored after annealing higher than 500 °C. The PL spectra of doped Ge-ncs samples show more intense exciton radiative luminescence than of undoped Ge-ncs sample, which is related to that the donor and acceptor impurities recombine the nonradiative centers in the interface of Ge-ncs and SiO2 matrix, and enhance the probability of exciton recombination. |
| Keywords: | 61.46.Hk 61.80.Hg 78.55.&minus m 78.30.&minus j |
| 本文献已被 ScienceDirect 等数据库收录！ | |