A method of magnetron sputtering followed by continuous-wave （cw） laser irradiation is developed to prepare crystalline silicon supersaturated with titanium. The irradiation of single crystalline Si samples sputtere...A method of magnetron sputtering followed by continuous-wave （cw） laser irradiation is developed to prepare crystalline silicon supersaturated with titanium. The irradiation of single crystalline Si samples sputtered with a thin layer of Ti is carried out under the 1064nm ew laser in a specially designed home-made facility. The thickness of the Si layer, within which the concentration of Ti surpasses the Mott limit, reaches 365 nm and the maximum concentration of Ti reaches 1.83 × 1021 cm-3. The crystalline structure of the Si samples is kept unchanged after cw laser irradiation. These results show that the current method can be an emcient way to obtain an intermediate band semiconductor material for solar cells.展开更多
A novel green-emitting phosphor Tb3＋ doped NaBaBO3 was prepared using a conventional high temperature solid-state reaction method. The crystal structure and luminescence properties of NaBaBO3：Tb3＋ were studied. The...A novel green-emitting phosphor Tb3＋ doped NaBaBO3 was prepared using a conventional high temperature solid-state reaction method. The crystal structure and luminescence properties of NaBaBO3：Tb3＋ were studied. The NaBaBO3 host was also investigated using density functional theory calculations. Our calculated lattice parameters of NaBaBO3 host were found to be in excellent agreement with experiment. Theoretically, the host matrix NaBaBO3 was a wide-gap semiconductor with a direct band gap of 3.66 eV, where the bottom of conduction band and the top of valence band were dominated by Ba 5d state and O 2p state, respectively. The excitation spectra indicated that the phosphor could be effectively excited by near ultraviolet light. The phosphor featured a satisfactory green performance with the highest photoluminescence intensity located at 543 nm excited by 377 nm light and the measured Commission Intemationale de L＇Eclairage （CIE） chromaticity was determined to be （0.2860, 0.4640）. The op- timum Tb3＋ concentration in NaBaBO3 was 5.0 mol.%. The concentration quenching occurred when Tb3＋ concentration was be- yond 5.0 mol.% and the concentration quenching mechanism could be explained by the dipole-dipole interaction. The effects of charge compensators （including Li, Na＋ and K＋） and temperature on the photoluminescence of NaBaBO3：Tb3＋ were also studied. The present work suggested that the NaBaBO3：Tb3＋ phosphor was a promising green-emitting material for near ultraviolet white light-emitting diodes.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61076056the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure of Shanghai Institute of Ceramics of Chinese Academy of Sciences under Grant No SKL201404SIC
文摘A method of magnetron sputtering followed by continuous-wave （cw） laser irradiation is developed to prepare crystalline silicon supersaturated with titanium. The irradiation of single crystalline Si samples sputtered with a thin layer of Ti is carried out under the 1064nm ew laser in a specially designed home-made facility. The thickness of the Si layer, within which the concentration of Ti surpasses the Mott limit, reaches 365 nm and the maximum concentration of Ti reaches 1.83 × 1021 cm-3. The crystalline structure of the Si samples is kept unchanged after cw laser irradiation. These results show that the current method can be an emcient way to obtain an intermediate band semiconductor material for solar cells.
基金supported by the National Natural Science Foundation of China(61076056)the Fundamental Research Funds for the Central Universities+1 种基金Program for New Century Excellent Talents in Fujian Province University(NCETFJ)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China
文摘A novel green-emitting phosphor Tb3＋ doped NaBaBO3 was prepared using a conventional high temperature solid-state reaction method. The crystal structure and luminescence properties of NaBaBO3：Tb3＋ were studied. The NaBaBO3 host was also investigated using density functional theory calculations. Our calculated lattice parameters of NaBaBO3 host were found to be in excellent agreement with experiment. Theoretically, the host matrix NaBaBO3 was a wide-gap semiconductor with a direct band gap of 3.66 eV, where the bottom of conduction band and the top of valence band were dominated by Ba 5d state and O 2p state, respectively. The excitation spectra indicated that the phosphor could be effectively excited by near ultraviolet light. The phosphor featured a satisfactory green performance with the highest photoluminescence intensity located at 543 nm excited by 377 nm light and the measured Commission Intemationale de L＇Eclairage （CIE） chromaticity was determined to be （0.2860, 0.4640）. The op- timum Tb3＋ concentration in NaBaBO3 was 5.0 mol.%. The concentration quenching occurred when Tb3＋ concentration was be- yond 5.0 mol.% and the concentration quenching mechanism could be explained by the dipole-dipole interaction. The effects of charge compensators （including Li, Na＋ and K＋） and temperature on the photoluminescence of NaBaBO3：Tb3＋ were also studied. The present work suggested that the NaBaBO3：Tb3＋ phosphor was a promising green-emitting material for near ultraviolet white light-emitting diodes.
