Empirical linear combination of atomic orbitals(LCAO)calculations are performed to investigate the electronic structure of Sb_(2)Se_(3),Sb_(2)Te_(3),In_(2)Se_(3) and In_(2)Te_(3).The bands of bonding p states are over...Empirical linear combination of atomic orbitals(LCAO)calculations are performed to investigate the electronic structure of Sb_(2)Se_(3),Sb_(2)Te_(3),In_(2)Se_(3) and In_(2)Te_(3).The bands of bonding p states are overlapped with the bands of lone pair states in these materials.The absorption edges of these materials correspond to indirect gap,and the calculation agrees with experimental values.展开更多
In recent years, using the ultra-vacuum PECVD system, we have successfully prepared the nano-crystalline silicon films (nc-Si:H). The nc-Si:H films are composed of a mass of fine microcrystallites with the mean grain ...In recent years, using the ultra-vacuum PECVD system, we have successfully prepared the nano-crystalline silicon films (nc-Si:H). The nc-Si:H films are composed of a mass of fine microcrystallites with the mean grain size of 3—5nm and the volume crystalline fraction of X_c=(50±5)%. The spacing between grains is constituted by a great number of interfaces, as shown in fig. 1. From the figure, it is estimated that the thickness of the interfaces is 1—4 atomic layers (≤1nm) and the volume fraction of the interfaces is about 40%. It is obvious that the microstructure of the nc-Si:H films is quite diffe展开更多
Hydrogenated nanocrystalline silicon films (nc-Si:H) are a developing novel man-made functional semiconductor material in recent years. Their strange microstructure and physical properties of nc-Si:H films are attract...Hydrogenated nanocrystalline silicon films (nc-Si:H) are a developing novel man-made functional semiconductor material in recent years. Their strange microstructure and physical properties of nc-Si:H films are attracting our attention. We have used the conventional structure analysis procedures, such as X-ray diffraction pattern, Raman scattering spectrum, high resolution transmission electron microscopy (HREM), and the scanning tunnelling microscope (STM), to analyze their microstructure. Since Mandelbrot proposed the fractal theory in 1982, it has become a quantitatively characterizing means to distinguish the microstructure morphology of materials. Recently, the fractal展开更多
文摘Empirical linear combination of atomic orbitals(LCAO)calculations are performed to investigate the electronic structure of Sb_(2)Se_(3),Sb_(2)Te_(3),In_(2)Se_(3) and In_(2)Te_(3).The bands of bonding p states are overlapped with the bands of lone pair states in these materials.The absorption edges of these materials correspond to indirect gap,and the calculation agrees with experimental values.
基金Project supported by the National Natural Science Foundation of China and the Science Foundation of Aeronautics Department, BNAA.
文摘In recent years, using the ultra-vacuum PECVD system, we have successfully prepared the nano-crystalline silicon films (nc-Si:H). The nc-Si:H films are composed of a mass of fine microcrystallites with the mean grain size of 3—5nm and the volume crystalline fraction of X_c=(50±5)%. The spacing between grains is constituted by a great number of interfaces, as shown in fig. 1. From the figure, it is estimated that the thickness of the interfaces is 1—4 atomic layers (≤1nm) and the volume fraction of the interfaces is about 40%. It is obvious that the microstructure of the nc-Si:H films is quite diffe
基金Project supported by the National Natural Science Foundation of China.
文摘Hydrogenated nanocrystalline silicon films (nc-Si:H) are a developing novel man-made functional semiconductor material in recent years. Their strange microstructure and physical properties of nc-Si:H films are attracting our attention. We have used the conventional structure analysis procedures, such as X-ray diffraction pattern, Raman scattering spectrum, high resolution transmission electron microscopy (HREM), and the scanning tunnelling microscope (STM), to analyze their microstructure. Since Mandelbrot proposed the fractal theory in 1982, it has become a quantitatively characterizing means to distinguish the microstructure morphology of materials. Recently, the fractal
