A brief history of the impurity theories in semiconductors is provided. A bound exciton model is proposed for both donor-and acceptor-like impurities and point defects, which offers a unified understanding for ＂shal...A brief history of the impurity theories in semiconductors is provided. A bound exciton model is proposed for both donor-and acceptor-like impurities and point defects, which offers a unified understanding for ＂shallow＂ and ＂deep＂impurities and point defects. The underlying physics of computational results using different density-functional theorybased approaches are discussed and interpreted in the framework of the bound exciton model.展开更多
The results of a study of the energy spectra of the activation of intrinsic defects of a photosensitive film made from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution depending on the condit...The results of a study of the energy spectra of the activation of intrinsic defects of a photosensitive film made from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution depending on the conditions of preparation and heat treatment in various media are presented. It is shown that at x = 0.8 cadmium vacancies create a deep level with an activation energy Е<sub>v</sub> + (0.63 ± 0.02) eV, a complex of chlorine atom with a cadmium vacancy creates a level Е<sub>v</sub> + (0.43 ± 0.02) eV, as well as the fast recombination center Еv + (0.92 ± 0.02) eV. The formation of selenium vacancies due to the introduction of chlorine and its combination with cadmium leads to the appearance of a sticking level Е<sub>c</sub> - (0.19 ± 0.02) eV. CdSe<sub>0.8</sub>S<sub>0.2</sub> films can be used to develop light emitting diodes, photo sensors, IR and visible lasers.展开更多
Copper doped n-type single-crystal silicon materials are prepared by a high temperature diffusion process. The electrical and thermal-sensitive characteristic of materials is investigated under different experimental ...Copper doped n-type single-crystal silicon materials are prepared by a high temperature diffusion process. The electrical and thermal-sensitive characteristic of materials is investigated under different experimental conditions. The results show that the maximum resistivity of 46.2 Ω·cm is obtained when the sample is treated at 1200℃ for 2 h with the surface concentration of the copper dopant source being 1.83×10^7mol/cm^2. The copper doped n-type silicon material presents a negative temperature-sensitive characteristic and the B values are about 3010–4130 K.展开更多
Silicon materials compensated by deep level impurities such as nickel and gold have negative temperature coefficient （NTC） characteristics. In this work, n-type silicon wafers are smeared by nickel chloride ethanol ...Silicon materials compensated by deep level impurities such as nickel and gold have negative temperature coefficient （NTC） characteristics. In this work, n-type silicon wafers are smeared by nickel chloride ethanol solution and gold chloric acid ethanol solution, and subsequently put in the opening environment to heat. The electrical resistance and B-value of the thermistors made by this silicon material are measured and analyzed. When the silicon surface concentration of gold atoms is 2 × 10-6 mol/cm2, the uniformity of the single-crystal silicon material is optimal. When the diffusion temperature is between 900 and 1000 ℃, a material with high B-value and low electrical resistivity is obtained. The B-T and R-T change laws calculated by the theory of semiconductor deep level energy are basically consistent with the experimental results.展开更多
基金supported by ARO/MURI (W911NF-101-0524 monitored by Dr. William Clark)ARO/Electronics (W911NF1610263 monitored by Dr. William Clark and Dr. Michele Gerhold)Bissell Distinguished Professorship at UNCC
文摘A brief history of the impurity theories in semiconductors is provided. A bound exciton model is proposed for both donor-and acceptor-like impurities and point defects, which offers a unified understanding for ＂shallow＂ and ＂deep＂impurities and point defects. The underlying physics of computational results using different density-functional theorybased approaches are discussed and interpreted in the framework of the bound exciton model.
文摘The results of a study of the energy spectra of the activation of intrinsic defects of a photosensitive film made from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution depending on the conditions of preparation and heat treatment in various media are presented. It is shown that at x = 0.8 cadmium vacancies create a deep level with an activation energy Е<sub>v</sub> + (0.63 ± 0.02) eV, a complex of chlorine atom with a cadmium vacancy creates a level Е<sub>v</sub> + (0.43 ± 0.02) eV, as well as the fast recombination center Еv + (0.92 ± 0.02) eV. The formation of selenium vacancies due to the introduction of chlorine and its combination with cadmium leads to the appearance of a sticking level Е<sub>c</sub> - (0.19 ± 0.02) eV. CdSe<sub>0.8</sub>S<sub>0.2</sub> films can be used to develop light emitting diodes, photo sensors, IR and visible lasers.
基金Project supported by the National High Technology Research and Development Program of China(No.2012AA091102)the National Natural Science Foundation of Xinjiang(No.2010211B24)
文摘Copper doped n-type single-crystal silicon materials are prepared by a high temperature diffusion process. The electrical and thermal-sensitive characteristic of materials is investigated under different experimental conditions. The results show that the maximum resistivity of 46.2 Ω·cm is obtained when the sample is treated at 1200℃ for 2 h with the surface concentration of the copper dopant source being 1.83×10^7mol/cm^2. The copper doped n-type silicon material presents a negative temperature-sensitive characteristic and the B values are about 3010–4130 K.
基金supported by the National High Technology Research and Development Program of China(No.2006AA03Z434)
文摘Silicon materials compensated by deep level impurities such as nickel and gold have negative temperature coefficient （NTC） characteristics. In this work, n-type silicon wafers are smeared by nickel chloride ethanol solution and gold chloric acid ethanol solution, and subsequently put in the opening environment to heat. The electrical resistance and B-value of the thermistors made by this silicon material are measured and analyzed. When the silicon surface concentration of gold atoms is 2 × 10-6 mol/cm2, the uniformity of the single-crystal silicon material is optimal. When the diffusion temperature is between 900 and 1000 ℃, a material with high B-value and low electrical resistivity is obtained. The B-T and R-T change laws calculated by the theory of semiconductor deep level energy are basically consistent with the experimental results.
