hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films w...hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films were investigated us-ing X-ray diffraction (XRD) , reflecting electron diffraction (RED) .scanning elec-tron microscopy (SEM) and ultraviolet visible absorption spectrometry (UV) .Theexperiments showed that the technique produced superior quality films of polycrys-tal ZnO_(1-x) (the O-vacancies in the ZnO lattice) , and possessed higher depositionrate, lower growth temperature conipared with CVD or MOCVD technique and thethin films had far better transparent photoconductive properties than tliose grownby the conventional CVD or MOCVD technique.展开更多
Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO acti...Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO active layer is deposited by radio frequency magnetron sputtering while a SiO2 gate insulator is formed by plasma-enhanced chemical vapor deposition. The saturation field-effect mobility and on/off ratio of the TTFT are improved by low temperature annealing in vacuum. Maximum saturation field-effect mobility and on/off ratio of 56.2 cm2/(V.s) and 3×10^5 are obtained, respectively. The transfer characteristics of the ZnSnO TPT are simulated using an analytical model and good agreement between measured and the calculated transfer characteristics is demonstrated.展开更多
The effects of annealing rate and morphology of sol–gel derived zinc oxide (ZnO) thin films on the performance of inverted polymer solar cells (IPSCs) are investigated. ZnO films with different morphologies are p...The effects of annealing rate and morphology of sol–gel derived zinc oxide (ZnO) thin films on the performance of inverted polymer solar cells (IPSCs) are investigated. ZnO films with different morphologies are prepared at different annealing rates and used as the electron transport layers in IPSCs. The undulating morphologies of ZnO films fabricated at annealing rates of 10 ℃/min and 3 ℃/min each possess a rougher surface than that of the ZnO film fabricated at a fast annealing rate of 50 ℃/min. The ZnO films are characterized by atomic force microscopy (AFM), optical transmittance measurements, and simulation. The results indicate that the ZnO film formed at 3 ℃/min possesses a good-quality contact area with the active layer. Combined with a moderate light-scattering, the resulting device shows a 16% improvement in power conversion efficiency compared with that of the rapidly annealed ZnO film device.展开更多
Modified textured surface boron-doped ZnO (ZnO:B) transparent conductive layers for thin-film solar cells were fabricated by low-pressure metal organic chemical vapor deposition (LP-MOCVD) on glass substrates. Th...Modified textured surface boron-doped ZnO (ZnO:B) transparent conductive layers for thin-film solar cells were fabricated by low-pressure metal organic chemical vapor deposition (LP-MOCVD) on glass substrates. These modified textured surface ZnO:B thin films included two layers. The first ZnO:B layer, which has a pyramid- shaped texture, was deposited under conventional growth conditions, and the second layer, which has a sphere- like structure, at a relatively lower growth temperature. Typical bi-layer ZnO:B thin films exhibit a high electron mobility of 27.6 cm^2/(V.s) due to improved grain boundary states. For bi-layer ZnO:B, the haze value increases and the total transmittance decreases with the increasing film thickness of the second modification layer. When applied in hydrogenated microcrystalline silicon (μc-Si:H) thin-film solar cells, the modified textured surface ZnO:B layers present relatively higher conversion efficiency than conventional ZnO:B films.展开更多
ZnO thin films were deposited on a glass substrate by dc (direct current) and rf (radio frequency) magnetron sputtering. Post-deposition annealing was performed in different atmospheres and at different temperatures. ...ZnO thin films were deposited on a glass substrate by dc (direct current) and rf (radio frequency) magnetron sputtering. Post-deposition annealing was performed in different atmospheres and at different temperatures. The correlation of the annealing conditions with the microstructure and properties of the ZnO films wer e investigated by ultraviolet-visible spectroscopy, X-ray diffraction, conductiv ity measurement and scanning electron microscopy. Only the strong 002 peak could be observed by X-ray diffraction. The post-deposition annealing of ZnO films wa s found to alter the film's microstructure and properties, including crystallini ty, porosity, grain size, internal stress level and resistivity. It was also fou nd that after annealing, the conductivity of poorly conductive samples often imp roved. However, annealing does not improve the conductivity of samples with high conductivity prior to annealing. The resistivity of as-grown films can be decre ased from 102 to 10-4Ω·cm after annealing in nitrogen. To explain the effects of annealing on the conductivity of ZnO, it is believed that annealing may alter the presence and distribution of oxygen defects, reduce the lattice stress, cau se diffusion, grain coarsening and recrystallization. Annealing will reduce the density of grain boundaries in less dense films, which may decrease the resistiv ity of the films. On the other hand, annealing may also increase the porosity of thin films, leading to an increase in resistivity.展开更多
文摘hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films were investigated us-ing X-ray diffraction (XRD) , reflecting electron diffraction (RED) .scanning elec-tron microscopy (SEM) and ultraviolet visible absorption spectrometry (UV) .Theexperiments showed that the technique produced superior quality films of polycrys-tal ZnO_(1-x) (the O-vacancies in the ZnO lattice) , and possessed higher depositionrate, lower growth temperature conipared with CVD or MOCVD technique and thethin films had far better transparent photoconductive properties than tliose grownby the conventional CVD or MOCVD technique.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61290305 and 91021020)the Natural Science Foundation of Zhejiang Province,China (Grant No.Z6100117)
文摘Annealing effect on the performance of fully transparent thin-film transistor (TTFT), in which zinc tin oxide (ZnSnO) is used as the channel material and SiO2 as the gate insulator, is investigated. The ZnSnO active layer is deposited by radio frequency magnetron sputtering while a SiO2 gate insulator is formed by plasma-enhanced chemical vapor deposition. The saturation field-effect mobility and on/off ratio of the TTFT are improved by low temperature annealing in vacuum. Maximum saturation field-effect mobility and on/off ratio of 56.2 cm2/(V.s) and 3×10^5 are obtained, respectively. The transfer characteristics of the ZnSnO TPT are simulated using an analytical model and good agreement between measured and the calculated transfer characteristics is demonstrated.
基金Project supported by the National Basic Research Program of China(Grant Nos.2011CBA00705,2011CBA00706,and 2011CBA00707)the National Natural Science Foundation of China(Grant No.61377031)
文摘The effects of annealing rate and morphology of sol–gel derived zinc oxide (ZnO) thin films on the performance of inverted polymer solar cells (IPSCs) are investigated. ZnO films with different morphologies are prepared at different annealing rates and used as the electron transport layers in IPSCs. The undulating morphologies of ZnO films fabricated at annealing rates of 10 ℃/min and 3 ℃/min each possess a rougher surface than that of the ZnO film fabricated at a fast annealing rate of 50 ℃/min. The ZnO films are characterized by atomic force microscopy (AFM), optical transmittance measurements, and simulation. The results indicate that the ZnO film formed at 3 ℃/min possesses a good-quality contact area with the active layer. Combined with a moderate light-scattering, the resulting device shows a 16% improvement in power conversion efficiency compared with that of the rapidly annealed ZnO film device.
基金supported by the State Key Development Program for Basic Research of China(Nos.2011CBA00705,2011CBA00706,2011CBA00707)the Tianjin Applied Basic Research Project and Cutting-Edge Technology Research Plan,China(No.13JCZDJC26900)+1 种基金the Tianjin Major Science and Technology Support Project,China(No.11TXSYGX22100)the Fundamental Research Funds for the Central Universities,China(No.65010341)
文摘Modified textured surface boron-doped ZnO (ZnO:B) transparent conductive layers for thin-film solar cells were fabricated by low-pressure metal organic chemical vapor deposition (LP-MOCVD) on glass substrates. These modified textured surface ZnO:B thin films included two layers. The first ZnO:B layer, which has a pyramid- shaped texture, was deposited under conventional growth conditions, and the second layer, which has a sphere- like structure, at a relatively lower growth temperature. Typical bi-layer ZnO:B thin films exhibit a high electron mobility of 27.6 cm^2/(V.s) due to improved grain boundary states. For bi-layer ZnO:B, the haze value increases and the total transmittance decreases with the increasing film thickness of the second modification layer. When applied in hydrogenated microcrystalline silicon (μc-Si:H) thin-film solar cells, the modified textured surface ZnO:B layers present relatively higher conversion efficiency than conventional ZnO:B films.
基金This work was supported by New Zealand Foundation for Research,Science and Technology(Top Achiever Doctoral Scholarship)Australian Institute of Nuclear Science and Engineering(Postgraduate Award).The authors would also like to thank Mrs.Catherine Hobbis for technical support.
文摘ZnO thin films were deposited on a glass substrate by dc (direct current) and rf (radio frequency) magnetron sputtering. Post-deposition annealing was performed in different atmospheres and at different temperatures. The correlation of the annealing conditions with the microstructure and properties of the ZnO films wer e investigated by ultraviolet-visible spectroscopy, X-ray diffraction, conductiv ity measurement and scanning electron microscopy. Only the strong 002 peak could be observed by X-ray diffraction. The post-deposition annealing of ZnO films wa s found to alter the film's microstructure and properties, including crystallini ty, porosity, grain size, internal stress level and resistivity. It was also fou nd that after annealing, the conductivity of poorly conductive samples often imp roved. However, annealing does not improve the conductivity of samples with high conductivity prior to annealing. The resistivity of as-grown films can be decre ased from 102 to 10-4Ω·cm after annealing in nitrogen. To explain the effects of annealing on the conductivity of ZnO, it is believed that annealing may alter the presence and distribution of oxygen defects, reduce the lattice stress, cau se diffusion, grain coarsening and recrystallization. Annealing will reduce the density of grain boundaries in less dense films, which may decrease the resistiv ity of the films. On the other hand, annealing may also increase the porosity of thin films, leading to an increase in resistivity.