Silica glasses doped with Bi2S3 microcystallite was prepared by the sol-gel process. Photoinduced second harmonic generation (SHG) was observed in the glass when it was irradiated with intense 1.06 mum and frequency d...Silica glasses doped with Bi2S3 microcystallite was prepared by the sol-gel process. Photoinduced second harmonic generation (SHG) was observed in the glass when it was irradiated with intense 1.06 mum and frequency doubled laser beams from a mode-locked Nd: YAG laser. It was found that the signal intensity increased with the irradiating time and approached a saturation gradually. The effect may be explained reasonably by the DC field model.展开更多
Cu2Se is a promising"phonon liquid-electron crystal"thermoelectric material with excellent thermoelectric performance.In this work,Cd-doped Cu2-xSeCdx(x=0,0.0075,0.01,and 0.02)samples were prepared using NaC...Cu2Se is a promising"phonon liquid-electron crystal"thermoelectric material with excellent thermoelectric performance.In this work,Cd-doped Cu2-xSeCdx(x=0,0.0075,0.01,and 0.02)samples were prepared using NaCl flux method.The solubility of Cd in Cu2Se at room temperature was less than 6%,and a second phase of CdSe was found in the samples with large initial Cd content(x=0.01 and 0.02).Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm.Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se.A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material,thus significantly enhancing its thermoelectric performance.With the increase in Cd content in the sample,the carrier concentration decreased and the mobility increased gradually.Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point.Excessive Cd doping led to the emergence of the second phase of CdSe in the sample,thus significantly increasing the thermal conductivity of the material.A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.展开更多
文摘Silica glasses doped with Bi2S3 microcystallite was prepared by the sol-gel process. Photoinduced second harmonic generation (SHG) was observed in the glass when it was irradiated with intense 1.06 mum and frequency doubled laser beams from a mode-locked Nd: YAG laser. It was found that the signal intensity increased with the irradiating time and approached a saturation gradually. The effect may be explained reasonably by the DC field model.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61864012 and 21701140)the Program for Innovative Research Team(in Science and Technology)in University of Yunnan Province,China.
文摘Cu2Se is a promising"phonon liquid-electron crystal"thermoelectric material with excellent thermoelectric performance.In this work,Cd-doped Cu2-xSeCdx(x=0,0.0075,0.01,and 0.02)samples were prepared using NaCl flux method.The solubility of Cd in Cu2Se at room temperature was less than 6%,and a second phase of CdSe was found in the samples with large initial Cd content(x=0.01 and 0.02).Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm.Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se.A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material,thus significantly enhancing its thermoelectric performance.With the increase in Cd content in the sample,the carrier concentration decreased and the mobility increased gradually.Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point.Excessive Cd doping led to the emergence of the second phase of CdSe in the sample,thus significantly increasing the thermal conductivity of the material.A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.
