The results of optical absorption analysis of the synthetic diamonds(type Ib) which were implanted with 40 keV molecular hydrogen ions at doses of 10^15-10^17H/cm^2(at 100K),showed that the increase of optical density...The results of optical absorption analysis of the synthetic diamonds(type Ib) which were implanted with 40 keV molecular hydrogen ions at doses of 10^15-10^17H/cm^2(at 100K),showed that the increase of optical density(OD) of modified layer(-140nm) in UV-VIS region was dependent upon the damage level caused by ion implantation process.The range of relative optical band gap(Er.opt) around 2.0eV suggested that an amorphous carbon network structure like a-C film,which probably contains some localized subtetrabedral-coordinated clusters embedded in the fourflod(sp^3) sites.was tentatively found in this layer,basing on the optical gap of carbon materials.The evolution of Er,opt with ion fluence indicated that no more hydrogenated carbon compositions were produced in as -implanted samples,while the increase of Er,opt with annealing temperature was very similar to that of hydrogen content dependence of Eopt in hydrogenately amorphous carbon(a-C:H):In addition the optical inhomogeneity of type Ib diamond has been revealed by a 2-dimension topograph in transmission mode at λ=430nm。展开更多
Ge^＋ ions are implanted into fused silica glass at room temperature and a fluence of 1 × 10^17 cm^-2. The as-implanted samples are annealed in O2, N2 and Ar atmospheres separately. Ge^0, GeO and GeO2 coexist in ...Ge^＋ ions are implanted into fused silica glass at room temperature and a fluence of 1 × 10^17 cm^-2. The as-implanted samples are annealed in O2, N2 and Ar atmospheres separately. Ge^0, GeO and GeO2 coexist in the as-implanted and annealed samples. Annealing in different atmospheres at 600℃ leads each composite to change its content. After annealing at 1000℃, there remains some amount of Ge^0 in the substrates. However, the content of Ge decreases due to out-diffusion. After annealing in N2, Si N composite is formed. The absorption peak of GeO appears at 240 nm after annealing in O2 atmosphere, and a new absorption peak occurs at 418 nm after annealing in N2 atmosphere, which is attributed to the Si N composite. There is no absorption peak appearing after annealing in Ar atmosphere. Transmission electron microscopic images confirm the formation of Ge nanoparticles in the as-implanted sample and GeO2 nanoparticles in the annealed sample. In the present study, the GeO content and the GeO2 content depend on annealing temperature and atmosphere. Three photolumineseence emission band peaks at 290, 385 and 415 nm appear after ion implantation and they become strong with the increase of annealing temperature below 700℃ and their photoluminescences recover to the values of as-grown samples after annealing at 700℃. Optical absorption and photoluminescence depend on the annealing temperature and atmosphere.展开更多
Pn junctions based on single crystalline tellurium supersaturated silicon were formed by ion implantation followed by pulsed laser melting（PLM）.P type silicon wafers were implanted with 245 keV ^126Te^＋ to a dose o...Pn junctions based on single crystalline tellurium supersaturated silicon were formed by ion implantation followed by pulsed laser melting（PLM）.P type silicon wafers were implanted with 245 keV ^126Te^＋ to a dose of 2×10^15 ions/cm^2,after a PLM process（248 nm,laser fluence of 0.30 and 0.35 J/cm^2,1-5 pulses,duration 30 ns）,an n^＋ type single crystalline tellurium supersaturated silicon layer with high carrier density（highest concentration 4.10×10^19 cm^3,three orders of magnitude larger than the solid solution limit） was formed,it shows high broadband optical absorption from 400 to 2500 nm.Current-voltage measurements were performed on these diodes under dark and one standard sun（AM 1.5）,and good rectification characteristics were observed.For present results,the samples with 4-5 pulses PLM are best.展开更多
利用金属蒸发真空多弧离子源（MEVVA源）注入机,将Au离子注入到高纯石英玻璃衬底中来制备Au纳米颗粒,Au离子注入的加速电压分别为20、40和60 k V,注入剂量为1×1017ions/cm2,随后将注入样品在普通管式退火炉中700~1000℃退火处理。...利用金属蒸发真空多弧离子源（MEVVA源）注入机,将Au离子注入到高纯石英玻璃衬底中来制备Au纳米颗粒,Au离子注入的加速电压分别为20、40和60 k V,注入剂量为1×1017ions/cm2,随后将注入样品在普通管式退火炉中700~1000℃退火处理。研究了注入条件和热退火参数对Au纳米颗粒的形成、生长、分布以及光学性能的影响。采用光学吸收谱、扫描电子显微镜和透射电子显微镜对注入样品的光学性能、表面形貌和微观结构进行了测试和表征。实验结果表明,采用该低压离子注入结合热退火工艺的方法,所制备的Au纳米颗粒具有很强的局域表面等离子体共振特性,同时该方法也为制备尺寸和分布可控的Au纳米颗粒提供了一些新的参考途径。展开更多
文摘The results of optical absorption analysis of the synthetic diamonds(type Ib) which were implanted with 40 keV molecular hydrogen ions at doses of 10^15-10^17H/cm^2(at 100K),showed that the increase of optical density(OD) of modified layer(-140nm) in UV-VIS region was dependent upon the damage level caused by ion implantation process.The range of relative optical band gap(Er.opt) around 2.0eV suggested that an amorphous carbon network structure like a-C film,which probably contains some localized subtetrabedral-coordinated clusters embedded in the fourflod(sp^3) sites.was tentatively found in this layer,basing on the optical gap of carbon materials.The evolution of Er,opt with ion fluence indicated that no more hydrogenated carbon compositions were produced in as -implanted samples,while the increase of Er,opt with annealing temperature was very similar to that of hydrogen content dependence of Eopt in hydrogenately amorphous carbon(a-C:H):In addition the optical inhomogeneity of type Ib diamond has been revealed by a 2-dimension topograph in transmission mode at λ=430nm。
基金Project supported by the Foundation for Young Scholars of University of Electronic Science and Technology of China (Grant No.L08010401JX0806)
文摘Ge^＋ ions are implanted into fused silica glass at room temperature and a fluence of 1 × 10^17 cm^-2. The as-implanted samples are annealed in O2, N2 and Ar atmospheres separately. Ge^0, GeO and GeO2 coexist in the as-implanted and annealed samples. Annealing in different atmospheres at 600℃ leads each composite to change its content. After annealing at 1000℃, there remains some amount of Ge^0 in the substrates. However, the content of Ge decreases due to out-diffusion. After annealing in N2, Si N composite is formed. The absorption peak of GeO appears at 240 nm after annealing in O2 atmosphere, and a new absorption peak occurs at 418 nm after annealing in N2 atmosphere, which is attributed to the Si N composite. There is no absorption peak appearing after annealing in Ar atmosphere. Transmission electron microscopic images confirm the formation of Ge nanoparticles in the as-implanted sample and GeO2 nanoparticles in the annealed sample. In the present study, the GeO content and the GeO2 content depend on annealing temperature and atmosphere. Three photolumineseence emission band peaks at 290, 385 and 415 nm appear after ion implantation and they become strong with the increase of annealing temperature below 700℃ and their photoluminescences recover to the values of as-grown samples after annealing at 700℃. Optical absorption and photoluminescence depend on the annealing temperature and atmosphere.
基金supported by the Beijing Natural Science Foundation(No.4122080)the State Key Development Program for Basic Research of China(No.2012CB934202)the CAS Program(No.Y072051002)
文摘Pn junctions based on single crystalline tellurium supersaturated silicon were formed by ion implantation followed by pulsed laser melting（PLM）.P type silicon wafers were implanted with 245 keV ^126Te^＋ to a dose of 2×10^15 ions/cm^2,after a PLM process（248 nm,laser fluence of 0.30 and 0.35 J/cm^2,1-5 pulses,duration 30 ns）,an n^＋ type single crystalline tellurium supersaturated silicon layer with high carrier density（highest concentration 4.10×10^19 cm^3,three orders of magnitude larger than the solid solution limit） was formed,it shows high broadband optical absorption from 400 to 2500 nm.Current-voltage measurements were performed on these diodes under dark and one standard sun（AM 1.5）,and good rectification characteristics were observed.For present results,the samples with 4-5 pulses PLM are best.
文摘利用金属蒸发真空多弧离子源（MEVVA源）注入机,将Au离子注入到高纯石英玻璃衬底中来制备Au纳米颗粒,Au离子注入的加速电压分别为20、40和60 k V,注入剂量为1×1017ions/cm2,随后将注入样品在普通管式退火炉中700~1000℃退火处理。研究了注入条件和热退火参数对Au纳米颗粒的形成、生长、分布以及光学性能的影响。采用光学吸收谱、扫描电子显微镜和透射电子显微镜对注入样品的光学性能、表面形貌和微观结构进行了测试和表征。实验结果表明,采用该低压离子注入结合热退火工艺的方法,所制备的Au纳米颗粒具有很强的局域表面等离子体共振特性,同时该方法也为制备尺寸和分布可控的Au纳米颗粒提供了一些新的参考途径。
