The p-NiO thin film is prepared by radio frequency magnetron sputtering on the n-GaN/sapphire substrate to form p-NiO/n-GaN heterojunction diodes.The structural,optical and electrical properties of the p-NiO thin film...The p-NiO thin film is prepared by radio frequency magnetron sputtering on the n-GaN/sapphire substrate to form p-NiO/n-GaN heterojunction diodes.The structural,optical and electrical properties of the p-NiO thin film are investigated.The results indicate that the NiO film has good crystal qualities and stable p-type conductivities.The current-voltage measurement of the p-NiO/n-GaN diode exhibits typical rectifying behaviour with a turn-on voltage of about 2.2 V.Under forward bias,a prominent ultraviolet emission centered at 375 nm is observed at room temperature.Furthermore,the mechanism of the light emission is discussed in terms of the band diagrams of the heterojunction in detail.展开更多
Arsenic doped p-type ZnO films were grown on n-type silicon substrates using the GaAs interlayer doping method.Under our growth conditions the main doping element is arsenic,which was confirmed by x-ray photoelectrosc...Arsenic doped p-type ZnO films were grown on n-type silicon substrates using the GaAs interlayer doping method.Under our growth conditions the main doping element is arsenic,which was confirmed by x-ray photoelectroscopy.X-ray diffraction measurements revealed that the p-ZnO:As film was still in the(002)preferred orientation.The Hall test showed that the hole concentration of the p-ZnO:As film was 2.6×1017 cm−3.The acceptor level was located at 135 meV above the valance band maximum,according to the low-temperature photoluminescence results.We then fabricated a p-ZnO:As/n-Si heterojunction light-emitting device.Its current-voltage curve showed the typical rectifying behavior of a p–n diode.At forward current injections,the electroluminescence peaks,which cover the ultraviolet-to-visible region,could be clearly detected.展开更多
NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical propertie...NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical properties of the films are researched in detail.The NiZnO films could retain a basic wurtzite structure when the Ni content is less than 0.18.As Ni content increases,crystal quality degradation could be observed in the x-ray diffraction patterns and a clear red shift of the absorption edge can be observed in the transmittance spectrum.Furthermore,the donor defects in the NiZnO film can be compensated for effectively by increasing the Ni content.The change of Ni content has an important effect on the properties of NiZnO films.展开更多
Background Central neurocytoma accounts for 0.1% of primary brain tumor that often occurs in young adults. Surgery is the main treatment for central neurocytoma and the rate of 5-year survival reaches up to over 90%. ...Background Central neurocytoma accounts for 0.1% of primary brain tumor that often occurs in young adults. Surgery is the main treatment for central neurocytoma and the rate of 5-year survival reaches up to over 90%. This study aimed to assess the effect of transcortical frontal approach to surgical resection of central neurocytoma on emotion and cognitive function 5 years after surgery. Methods Telephone following-up visits were used in this study. By means of neuropsychological testing, assayed emotion, memory and abstract thinking ability of 18 patients undergoing central neurocytoma resection by transcortical frontal approach for 5 years or more, with another 21 normal cases as control group were enrolled. The data were analyzed statisticaJly by paired t test with SPSS11.5. Results Patients whose central neurocytoma was removed by transcortical frontal approach were not affected on calculating ability 5 years after operation while ability of memory declined sharply （P=-0.000）, the older, the more sharply （P=0.036）. Ability of abstract thinking was significantly reduced （P=0.000）, the older, the more significantly as well （P=-0.012）; additionally, anxiety and depression occurred in patients rather more than those of control group （P=0.000）, especially cognitive impairment. Conclusions Transcortical frontal approach for surgical resection of central neurocytoma has certain long-term influence on patients＇ life quality, vulnerable to anxiety, depression and cognitive impairment, the severity of which was correlated to age. Therefore, imDrovina suroical aoDroach will be of value for better Iona-term life aualitv of oatients.展开更多
基金Supported by the National Basic Research Program of China(2011CB302005)the National Natural Science Foundation of China(61006006,60877020,60976010)+1 种基金the Science and Technology Development Project in Jilin Province(20100170)the Fundamental Research Funds for the Central Universities(dut11rc(3)45).
文摘The p-NiO thin film is prepared by radio frequency magnetron sputtering on the n-GaN/sapphire substrate to form p-NiO/n-GaN heterojunction diodes.The structural,optical and electrical properties of the p-NiO thin film are investigated.The results indicate that the NiO film has good crystal qualities and stable p-type conductivities.The current-voltage measurement of the p-NiO/n-GaN diode exhibits typical rectifying behaviour with a turn-on voltage of about 2.2 V.Under forward bias,a prominent ultraviolet emission centered at 375 nm is observed at room temperature.Furthermore,the mechanism of the light emission is discussed in terms of the band diagrams of the heterojunction in detail.
基金Supported by the National Basic Research Program of China under Grant No.2011CB302000the National High-Technology Research and Development Program of China under Grant No.2009AA03Z401+1 种基金the National Natural Science Foundation of China under Grant Nos.61076045,11004020,60877020 and 60976010the China Postdoctoral Science Foundation under Grant No.20110491539.
文摘Arsenic doped p-type ZnO films were grown on n-type silicon substrates using the GaAs interlayer doping method.Under our growth conditions the main doping element is arsenic,which was confirmed by x-ray photoelectroscopy.X-ray diffraction measurements revealed that the p-ZnO:As film was still in the(002)preferred orientation.The Hall test showed that the hole concentration of the p-ZnO:As film was 2.6×1017 cm−3.The acceptor level was located at 135 meV above the valance band maximum,according to the low-temperature photoluminescence results.We then fabricated a p-ZnO:As/n-Si heterojunction light-emitting device.Its current-voltage curve showed the typical rectifying behavior of a p–n diode.At forward current injections,the electroluminescence peaks,which cover the ultraviolet-to-visible region,could be clearly detected.
基金by the National Basic Research Program of China under Grant No 2011CB30200001the National Natural Science Foundation of China under Grant Nos 61006006,60877020,60976010 and 61076045the Science and Technology Development Project in Jilin Province(No 20100170).
文摘NiZnO thin films are grown on c-plane sapphire substrates by using a photo-assisted metal organic chemical vapor deposition(MOCVD)system.The effect of the Ni content on the crystalline,optical and electrical properties of the films are researched in detail.The NiZnO films could retain a basic wurtzite structure when the Ni content is less than 0.18.As Ni content increases,crystal quality degradation could be observed in the x-ray diffraction patterns and a clear red shift of the absorption edge can be observed in the transmittance spectrum.Furthermore,the donor defects in the NiZnO film can be compensated for effectively by increasing the Ni content.The change of Ni content has an important effect on the properties of NiZnO films.
基金This work was supported by grants from the Project for Science and Technology Commission of Shanghai Municipality （No. 10JC1402200 and No. 08411953600）, the Project for the National Science Foundation for Distinguished Young Scholars of China （No. 81025013）, the Project for the National Natural Science Foundation of China （No. 30872655）, the Project for National ＂985＂ Engineering of China, the ＂Dawn Tracking＂ Program of Shanghai Education Commission, China （No. 10GG01）.
文摘Background Central neurocytoma accounts for 0.1% of primary brain tumor that often occurs in young adults. Surgery is the main treatment for central neurocytoma and the rate of 5-year survival reaches up to over 90%. This study aimed to assess the effect of transcortical frontal approach to surgical resection of central neurocytoma on emotion and cognitive function 5 years after surgery. Methods Telephone following-up visits were used in this study. By means of neuropsychological testing, assayed emotion, memory and abstract thinking ability of 18 patients undergoing central neurocytoma resection by transcortical frontal approach for 5 years or more, with another 21 normal cases as control group were enrolled. The data were analyzed statisticaJly by paired t test with SPSS11.5. Results Patients whose central neurocytoma was removed by transcortical frontal approach were not affected on calculating ability 5 years after operation while ability of memory declined sharply （P=-0.000）, the older, the more sharply （P=0.036）. Ability of abstract thinking was significantly reduced （P=0.000）, the older, the more significantly as well （P=-0.012）; additionally, anxiety and depression occurred in patients rather more than those of control group （P=0.000）, especially cognitive impairment. Conclusions Transcortical frontal approach for surgical resection of central neurocytoma has certain long-term influence on patients＇ life quality, vulnerable to anxiety, depression and cognitive impairment, the severity of which was correlated to age. Therefore, imDrovina suroical aoDroach will be of value for better Iona-term life aualitv of oatients.
