Li-N dual-doped ZnO films [ZnO：（Li,N）] with Li doping concentrations of 3 at.%-5 at.% were grown on a glass substrate using an ion beam enhanced deposition （IBED） method. An optimal p-type ZnO：（Li,N） film with...Li-N dual-doped ZnO films [ZnO：（Li,N）] with Li doping concentrations of 3 at.%-5 at.% were grown on a glass substrate using an ion beam enhanced deposition （IBED） method. An optimal p-type ZnO：（Li,N） film with the resistivity of 11.4 Ω·cm was obtained by doping 4 at.% of Li and 5 sccm flow ratio of N2. The ZnO：（Li,N） films-exhibited a wurtzite structure and good transmittance in the visible region. The p-type conductive mechanism of ZnO：（Li,N） films are attributed to the Li substitute Zn site （Lizn） acceptor. N doping in ZnO can forms the Lii-No complex, which depresses the compensation of Li occupy interstitial site （Lii） donors for Lizn acceptor and helps to achieve p-type ZnO：（Li,N） films. Room temperature photoluminescence measurements indicate that the UV peak （381 nm） is due to the shallow acceptors Lizn in the p-type ZnO：（Li,N） films. The band gap of the ZnO：（Li,N） films has a red-shift after p-type doping.展开更多
The n-ZnO/p-Si heterojunction was fabricated by depositing high quality single crystalline aluminium-doped n-type ZnO film on p-type Si using the laser molecular beam epitaxy technique. The heterojunction exhibited a ...The n-ZnO/p-Si heterojunction was fabricated by depositing high quality single crystalline aluminium-doped n-type ZnO film on p-type Si using the laser molecular beam epitaxy technique. The heterojunction exhibited a good rectifying behavior. The electrical properties of the heterojunction were investigated by means of temperature dependence current density-voltage measurements. The mechanism of the current transport was proposed based on the band structure of the heterojunction. When the applied bias V is lower than 0.15 V, the current follows the Ohmic behavior. When 0.15 V ~ V 〈 0.6 V, the transport property is dominated by diffusion or recombination in the junction space charge region, while at higher voltages （V 〉 0.6 V）, the space charge limited effect becomes the main transport mechanism. The current-voltage characteristic under illumination was also investigated. The photovoltage and the short circuit current density of the heterojunction aproached 270 mV and 2.10 mA/cm^2, respectively.展开更多
A zinc oxide thin film in cubic crystalline phase, which is usually prepared under high pressure, has been grown on the Mg O（001） substrate by a three-step growth using plasma-assisted molecular beam epitaxy. The cu...A zinc oxide thin film in cubic crystalline phase, which is usually prepared under high pressure, has been grown on the Mg O（001） substrate by a three-step growth using plasma-assisted molecular beam epitaxy. The cubic structure is confirmed by in-situ reflection high energy electron diffraction measurements and simulations. The x-ray photoelectron spectroscopy reveals that the outer-layer surface of the film（less than 5 nm thick） is of ZnO phase while the buffer layer above the substrate is of ZnMgO phase, which is further confirmed by the band edge transmissions at the wavelengths of about 390 nm and 280 nm, respectively. The x-ray diffraction exhibits no peaks related to wurtzite ZnO phase in the film. The cubic ZnO film is presumably considered to be of the rock-salt phase. This work suggests that the metastable cubic ZnO films, which are of applicational interest for p-type doping, can be epitaxially grown on the rock-salt substrates without the usually needed high pressure conditions.展开更多
文摘Li-N dual-doped ZnO films [ZnO：（Li,N）] with Li doping concentrations of 3 at.%-5 at.% were grown on a glass substrate using an ion beam enhanced deposition （IBED） method. An optimal p-type ZnO：（Li,N） film with the resistivity of 11.4 Ω·cm was obtained by doping 4 at.% of Li and 5 sccm flow ratio of N2. The ZnO：（Li,N） films-exhibited a wurtzite structure and good transmittance in the visible region. The p-type conductive mechanism of ZnO：（Li,N） films are attributed to the Li substitute Zn site （Lizn） acceptor. N doping in ZnO can forms the Lii-No complex, which depresses the compensation of Li occupy interstitial site （Lii） donors for Lizn acceptor and helps to achieve p-type ZnO：（Li,N） films. Room temperature photoluminescence measurements indicate that the UV peak （381 nm） is due to the shallow acceptors Lizn in the p-type ZnO：（Li,N） films. The band gap of the ZnO：（Li,N） films has a red-shift after p-type doping.
基金Project supported by the Postdoctor Foundation of Hebei Province, Chinathe Natural Science Foundation of Hebei Province,China (Grant No. F2012201093)the Natural Science Foundation of Hebei University, China (Grant No. 2008127)
文摘The n-ZnO/p-Si heterojunction was fabricated by depositing high quality single crystalline aluminium-doped n-type ZnO film on p-type Si using the laser molecular beam epitaxy technique. The heterojunction exhibited a good rectifying behavior. The electrical properties of the heterojunction were investigated by means of temperature dependence current density-voltage measurements. The mechanism of the current transport was proposed based on the band structure of the heterojunction. When the applied bias V is lower than 0.15 V, the current follows the Ohmic behavior. When 0.15 V ~ V 〈 0.6 V, the transport property is dominated by diffusion or recombination in the junction space charge region, while at higher voltages （V 〉 0.6 V）, the space charge limited effect becomes the main transport mechanism. The current-voltage characteristic under illumination was also investigated. The photovoltage and the short circuit current density of the heterojunction aproached 270 mV and 2.10 mA/cm^2, respectively.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204253,U1232110,U1332105,61227009,and 91321102)the Fundamental Research Funds for Central Universities,China(Grant No.2013SH001)the National High Technology Research and Development Program of China(Grant No.2014AA052202)
文摘A zinc oxide thin film in cubic crystalline phase, which is usually prepared under high pressure, has been grown on the Mg O（001） substrate by a three-step growth using plasma-assisted molecular beam epitaxy. The cubic structure is confirmed by in-situ reflection high energy electron diffraction measurements and simulations. The x-ray photoelectron spectroscopy reveals that the outer-layer surface of the film（less than 5 nm thick） is of ZnO phase while the buffer layer above the substrate is of ZnMgO phase, which is further confirmed by the band edge transmissions at the wavelengths of about 390 nm and 280 nm, respectively. The x-ray diffraction exhibits no peaks related to wurtzite ZnO phase in the film. The cubic ZnO film is presumably considered to be of the rock-salt phase. This work suggests that the metastable cubic ZnO films, which are of applicational interest for p-type doping, can be epitaxially grown on the rock-salt substrates without the usually needed high pressure conditions.
基金Project supported by the Key Project of National Natural Science Foundation of China(50532050)the"973"program (2006CB604906)+1 种基金the Knowledge Innovation Project of Chinese Academy of Sciencesthe National Natural Science Foundation of China(60806002,60506014,10874178,10674133,60776011)~~
