Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circu...Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circuit voltage with a rise time of about 10 ns and full width at half maximum of about 28 ns is detected when the film surface is irradiated by a 308-nm laser pulse with a duration of 25 ns. Besides, opemcircuit voltage signals are also observed when the film surface is irradiated separately by the laser pulses of 532 nm and 1064 nm. The results indicate that Ca3Co4O9 thin films have a great potential application in the wide range photodetctor from the ultraviolet to near infrared regions.展开更多
Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel...Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel chelates and Cu (NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose. YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate, following vacuum drying, rapid calcining, firing and oxygen annealing. The prepared films were characterized by optical microscope (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that films were crack-free and homogeneous, stronger tendency of (00l) texture, uniform with less pore, pure c-axis orientation. The films showed good superconducting properties, with Tc of 90 K and critical current density (Jc) of 1 MA/cm2 (77 K, 0 T). This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.展开更多
Ca3Co409 thin films have been first prepared on polycrystalline AI203 substrates using chemical solution deposition method by multiple annealing processing. It is observed that the derived thin films are c-axis orient...Ca3Co409 thin films have been first prepared on polycrystalline AI203 substrates using chemical solution deposition method by multiple annealing processing. It is observed that the derived thin films are c-axis oriented although the substrates are polycrystalline AI203 substrates, suggesting the self-assembled c-axis orientation. The annealing temperature effects on the properties are investigated and discussed. The best performances are attributed to the 850 ℃-annealed sample, whose resistivity, Seebeck coefficient and power factor at 300 K are 7.4 mΩ cm, 117 μV/K and 0.18 mW/m K-2 respectively, which is even better than those of the thin films deposited on single crystal substrates. The results will provide an effective route to optimize the properties of Ca3Co409 thin films using chemical solution deposition by multiple annealing processing even the substrates are polycrystalline.展开更多
High transparency in visible region was required for red-light-emitting Y2O3:Eu3+ thin film phosphors. Such films were obtained via chemical bath deposition on bare SiO2 glass substrates through heterogeneous nucleati...High transparency in visible region was required for red-light-emitting Y2O3:Eu3+ thin film phosphors. Such films were obtained via chemical bath deposition on bare SiO2 glass substrates through heterogeneous nucleation with further heat treatment. Thin amorphous yttrium basic carbonate films could be completely transformed to crystalline Y2O3 at 650 °C. X-ray diffraction and field-emission scanning electron microscopy were used to characterize these products. The deposition temperature and the post-anneali...展开更多
Nickel oxide(NiOx),a p-type oxide semiconductor,has gained significant attention due to its versatile and tunable properties.It has become one of the critical materials in wide range of electronics applications,includ...Nickel oxide(NiOx),a p-type oxide semiconductor,has gained significant attention due to its versatile and tunable properties.It has become one of the critical materials in wide range of electronics applications,including resistive switching random access memory devices and highly sensitive and selective sensor applications.In addition,the wide band gap and high work function,coupled with the low electron affinity,have made NiOx widely used in emerging optoelectronics and p-n heterojunctions.The properties of NiOx thin films depend strongly on the deposition method and conditions.Efficient implementation of NiOx in next-generation devices will require controllable growth and processing methods that can tailor the morphological and electronic properties of the material,but which are also compatible with flexible substrates.In this review,we link together the fundamental properties of NiOx with the chemical processing methods that have been developed to grow the material as thin films,and with its application in electronic devices.We focus solely on thin films,rather than NiOx incorporated with one-dimensional or two-dimensional materials.This review starts by discussing how the p-type nature of NiOx arises and how its stoichiometry affects its electronic and magnetic properties.We discuss the chemical deposition techniques for growing NiOx thin films,including chemical vapor deposition,atomic layer deposition,and a selection of solution processing approaches,and present examples of recent progress made in the implementation of NiOx thin films in devices,both on rigid and flexible substrates.Furthermore,we discuss the remaining challenges and limitations in the deposition of device-quality NiOx thin films with chemical growth methods.展开更多
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 10904030)the Natural Science Foundation of Hebei Province, China (Grant No. A2009000144)
文摘Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circuit voltage with a rise time of about 10 ns and full width at half maximum of about 28 ns is detected when the film surface is irradiated by a 308-nm laser pulse with a duration of 25 ns. Besides, opemcircuit voltage signals are also observed when the film surface is irradiated separately by the laser pulses of 532 nm and 1064 nm. The results indicate that Ca3Co4O9 thin films have a great potential application in the wide range photodetctor from the ultraviolet to near infrared regions.
基金National High Technology Research and Development Program of China ("863" Program) (2009AA03Z203)
文摘Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel chelates and Cu (NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose. YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate, following vacuum drying, rapid calcining, firing and oxygen annealing. The prepared films were characterized by optical microscope (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that films were crack-free and homogeneous, stronger tendency of (00l) texture, uniform with less pore, pure c-axis orientation. The films showed good superconducting properties, with Tc of 90 K and critical current density (Jc) of 1 MA/cm2 (77 K, 0 T). This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.
基金supported by the National Natural Science Foundation of China (Nos. 50802096, 10904150 and10904151)
文摘Ca3Co409 thin films have been first prepared on polycrystalline AI203 substrates using chemical solution deposition method by multiple annealing processing. It is observed that the derived thin films are c-axis oriented although the substrates are polycrystalline AI203 substrates, suggesting the self-assembled c-axis orientation. The annealing temperature effects on the properties are investigated and discussed. The best performances are attributed to the 850 ℃-annealed sample, whose resistivity, Seebeck coefficient and power factor at 300 K are 7.4 mΩ cm, 117 μV/K and 0.18 mW/m K-2 respectively, which is even better than those of the thin films deposited on single crystal substrates. The results will provide an effective route to optimize the properties of Ca3Co409 thin films using chemical solution deposition by multiple annealing processing even the substrates are polycrystalline.
基金Project supported by the National Basic Research Program of China (2007CB936704)Major Basic Research Program of Shanghai (07DJ14001)+2 种基金"Pujiang Talent Project" of Shanghai Science and Technology Committee (09PJ1410600)Innovation Group for the Ministry of Science and Technology of ChinaPHD Innovation Program 2009 by NSRL of Ministry of Education
文摘High transparency in visible region was required for red-light-emitting Y2O3:Eu3+ thin film phosphors. Such films were obtained via chemical bath deposition on bare SiO2 glass substrates through heterogeneous nucleation with further heat treatment. Thin amorphous yttrium basic carbonate films could be completely transformed to crystalline Y2O3 at 650 °C. X-ray diffraction and field-emission scanning electron microscopy were used to characterize these products. The deposition temperature and the post-anneali...
基金Aziz FoundationDowning College,Cambridge+2 种基金Engineering and Physical Sciences Research Council,Grant/Award Numbers:EP/L016087/1,EP/P027032/1Isaac Newton TrustRoyal Academy of Engineering,Grant/Award Number:RF\201718\1701 and CieT1819\24。
文摘Nickel oxide(NiOx),a p-type oxide semiconductor,has gained significant attention due to its versatile and tunable properties.It has become one of the critical materials in wide range of electronics applications,including resistive switching random access memory devices and highly sensitive and selective sensor applications.In addition,the wide band gap and high work function,coupled with the low electron affinity,have made NiOx widely used in emerging optoelectronics and p-n heterojunctions.The properties of NiOx thin films depend strongly on the deposition method and conditions.Efficient implementation of NiOx in next-generation devices will require controllable growth and processing methods that can tailor the morphological and electronic properties of the material,but which are also compatible with flexible substrates.In this review,we link together the fundamental properties of NiOx with the chemical processing methods that have been developed to grow the material as thin films,and with its application in electronic devices.We focus solely on thin films,rather than NiOx incorporated with one-dimensional or two-dimensional materials.This review starts by discussing how the p-type nature of NiOx arises and how its stoichiometry affects its electronic and magnetic properties.We discuss the chemical deposition techniques for growing NiOx thin films,including chemical vapor deposition,atomic layer deposition,and a selection of solution processing approaches,and present examples of recent progress made in the implementation of NiOx thin films in devices,both on rigid and flexible substrates.Furthermore,we discuss the remaining challenges and limitations in the deposition of device-quality NiOx thin films with chemical growth methods.
