共查询到20条相似文献,搜索用时 901 毫秒
1.
M. C. Kao H. Z. Chen S. L. Young 《Applied Physics A: Materials Science & Processing》2010,98(3):595-599
The preferred (002) orientation zinc oxide (ZnO) nanocrystalline thin films have been deposited on FTO-coated glass substrates
by sol–gel spin-coating technology and rapid thermal annealing for use in dye-sensitized solar cells (DSSC). The effects of
preannealing temperature (100 and 300°C) on the microstructure, morphology and optical properties of ZnO thin films were studied.
The ZnO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM) and Brunauer–Emmett–Teller
(BET) analysis. The photoelectric performance of DSSC was studied by I–V curve and the incident photon-to-current conversion efficiency (IPCE), respectively. From the results, the intensities of
(002) peaks of ZnO thin films increases with increasing preannealing temperature from 100°C to 300°C. The increase in pore
size and surface area of ZnO films crystallized at the increased preannealing temperature contributed to the improvement on
the absorption of N3 dye onto the films, the short-circuit photocurrent (J
sc) and open-circuit voltage (V
oc) of DSSC. The higher efficiency (η) of 2.5% with J
sc and V
oc of 8.2 mA/cm2 and 0.64 V, respectively, was obtained by the ZnO film preannealed at 300°C. 相似文献
2.
Poly(N-vinyl caprolactam) (PNVCL) side chains were grafted to a poly(vinyl chloride) (PVC) backbone via atom transfer radical polymerization.
The synthesized PVC-g-PNVCL graft copolymer was templated for the preparation of porous TiO2 thin films, which involved a sol–gel reaction and calcination process. The interaction of the carbonyl groups in the PVC-g-PNVCL with the titania was revealed by FT-IR spectroscopy. X-ray diffraction and transmission electron microscopy analysis
showed the formation of porous TiO2 thin films with the anatase phase. A series of porous TiO2 thin films with different pore sizes and porosities was prepared by varying the solution compositions and were used as photoelectrodes
in dye-sensitized solar cells (DSSC) with a polymer electrolyte. The DSSC performed best when using the TiO2 film with higher porosity, lower interfacial resistance, and longer electron life time. The highest energy conversion efficiency,
photovoltage (V
oc), photocurrent density (J
sc), and fill factor (FF) were 1.2%, 0.68 V, 3.2 mA/cm2, and 0.57 at 100 mW/cm2, respectively, for the quasi-solid state DSSC with a 730-nm-thick TiO2 film. 相似文献
3.
Hai Wang Yong Liu Ming Li Hong Huang Minyi Zhong Hui Shen 《Applied Physics A: Materials Science & Processing》2009,97(1):25-29
Large-scale macroporous TiO2 nanowires (MTN) were directly grown on spiral-shaped titanium wires as photoanodes of dye-sensitized solar cells (DSSCs)
via a facile hydrothermal reaction without any seeds, templates, and TiO2 powder. The MTN thin film was characterized by SEM, XRD and TEM. The studies revealed that the MTN thin film had better mechanical
properties and provided an efficient pathway for the diffusion of liquid electrolyte. The efficiency of 0.86% for the 3D DSSC
was obtained with a J
sc of 2.30 mA/cm2, V
oc of 616 mV, and FF of 0.61. This MNT-based mini 3D DSSC is a promising photovoltaic device for applications in the fields
of high-integrated micro-electronic equipment. 相似文献
4.
Chul‐Kyu Lee Se Yeob Park Hong Yoon Jung Chang‐Kyu Lee Byeong‐Geun Son Hyo Jin Kim Young‐Joo Lee Young‐Chang Joo Jae Kyeong Jeong 《固体物理学:研究快报》2013,7(3):196-198
Zn–Sn–O (ZTO) thin film transistors (TFTs) were fabricated with a Cu source/drain electrode. Although a reasonably high mobility (μFE) of 13.2 cm2/Vs was obtained for the ZTO TFTs, the subthreshold gate swing (SS) and threshold voltage (Vth) of 1.1 V/decade and 9.1 V, respectively, were inferior. However, ZTO TFTs with Ta film inserted as a diffusion barrier, exhibited improved SS and Vth values of 0.48 V/decade and 3.0 V, respectively as well as a high μFE value of 18.7 cm2/Vs. The improvement in the Ta‐inserted device was attributed to the suppression of Cu lateral diffusion into the ZTO channel region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
Hai Wang Yong Liu Hong Huang Minyi Zhong Hui Shen Yuanhao Wang Hongxing Yang 《Applied Surface Science》2009,255(22):9020-9025
Low resistance dye-sensitized solar cells (DSSCs) based on all-titanium substrates were proposed in this paper. To minimize the internal resistance of DSSCs, the titanium wires and titanium sheets were used as the substrates of the photoanode and the counter electrode, respectively. Compared with the FTO substrate, titanium wires could absorb much diffused light by back reflection since the reflectivity in the titanium sheet was highly increased up to 53.12%. Furthermore, the transmittance of the front cover was increased by 13.2% using the super white glass instead of FTO substrate. The thickness of TiO2 thin film coated on titanium wire was optimized to achieve a high cell performance. The efficiency of 5.6% for the cell was obtained with a Jsc of 15.41 mA cm−2, Voc of 0.59 V, and FF of 0.62. The results showed that the titanium-based DSSCs had superiority for producing the large-scale DSSCs without metal grid line. 相似文献
6.
Cheng-Fu Yang Hong-Hsin Huang Cheng-Yi Chen Ping-Chih Huang Chien-Chen Diao 《Applied Physics A: Materials Science & Processing》2009,94(1):117-122
In this study, two different thin films, TiO2 thin film and TiO2–W–TiO2 multi-layer thin films (W, tungsten), are prepared by RF magnetron sputtering onto glass substrates. The crystal structure,
morphology, and transmittance of TiO2 and TiO2–W–TiO2 multi-layer thin films are investigated by X-ray diffraction, SEM, and UV-Vis spectrometer, respectively. The amorphous,
rutile, and anatase TiO2 phases are observed in the TiO2 thin film and in the TiO2–W–TiO2 multi-layer thin films. The deposition of tungsten as the inter-layer will have large effect on the transmittance and phase
ratios of rutile and anatase phases in the TiO2–W–TiO2 multi-layer thin films. The crystal intensities of amorous TiO2 will decrease as the tungsten is used as the middle layer in the multi-layer structure. The band gap energy values of TiO2 thin film and TiO2–W–TiO2 multi-layer thin films are evaluated from (αhν)1/2 versus energy plots, and the calculated results show that the energy gap decreases from 3.21 eV (TiO2 thin film) to 3.08∼3.03 EV (TiO2–W–TiO2 multi-layer thin films). 相似文献
7.
High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process
Qian Zhang Guodong Xia Lubin Li Wenwen Xia Hongyu Gong Sumei Wang 《Current Applied Physics》2019,19(2):174-181
Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300–600?°C revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500?°C showed a high carrier mobility of 5.9?cm2/V, high on/off current ratio (Ion/off) of 106-107, and threshold voltage (Vth) of 1.03?V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ZrTiOx TFTs showed high mobility of 17.9?cm2/V and Ion/off of 105-106?at a low operation voltage of 3?V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices. 相似文献
8.
A nanoparticle TiO2 solid-state photoelectrochemical cell utilizing as a solid electrolyte of poly(acrylonitrile)–propylene–carbonate–lithium
perchlorate (PAN–PC–LiClO4) has been fabricated. The performance of the device has been tested in the dark and under illumination of 100-mW cm−2 light. A nanoparticle TiO2 film was deposited onto indium tin oxide-covered glass substrate by controlled hydrolysis technique assisted with spin-coating
technique. The average grain size for the TiO2 film is 76 nm. LiClO4 salt was used as a redox couple. The room temperature conductivity of the electrolyte is 4.2 × 10−4 S cm−1. A graphite electrode was prepared onto a glass slide by electron beam evaporation technique. The device shows the rectification
property in the dark and shows the photovoltaic effect under illumination. The best J
sc and V
oc of the device were 2.82 μA cm−2 and V
oc of 0.58 V, respectively, obtained at the conductivity of 4.2 × 10−4 S cm−1 and intensity of 100 mW cm−2. The J
sc was improved by about three times by introducing nanoparticle TiO2 and by using a solid electrolyte of PAN–PC–LiClO4 replacing PVC–PC–LiClO4 in the device. The current transport mechanism of the cell is also presented in this paper. 相似文献
9.
An increasing energy demand and environmental pollution create a pressing need for clean and sustainable energy solutions.
TiO2 semiconductor material is expected to play an important role in helping solve the energy crisis through effective utilization
of solar energy based on photovoltaic devices. Dye-sensitized solar cells (DSSCs) are potentially lower cost alternative to
inorganic silicon-based photovoltaic cells. In this study, we report on the fabrication of DSSCs from anodic TiO2 nanotubes (NT) powder, produced by rapid breakdown potentiostatic anodization of Ti foil in 0.1 M HClO4 electrolyte, as photoanode. TiO2 NT powders with a typical NT outer diameter of approximately 40 nm, wall thickness of approximately 8–15 nm, and length of
about 20–25 μm, have been synthesized. The counter electrode was made by electrodeposition of Pt from an aqueous solution
of 5 mM H2PtCl6 onto fluorine-doped tin oxide (FTO) glass substrate. The above front-side illuminated DSSCs were compared with back-side
illuminated DSSCs fabricated from anodic TiO2 NTs that were grown on the top of Ti foil as photoanode. The highest cell efficiency was 3.54% under 100 mW/cm2 light intensity (1 sun AM 1.5G light, Jsc = 14.3 mA/cm2, Voc = 0.544 V, FF = 0.455). To the best of our knowledge, this is the first report on the fabrication of DSSC from anodic
TiO2 NTs powder. The TiO2/FTO photoanodes were characterized by FE-SEM, XRD, and UV–Visible spectroscopy. The catalytic properties of Pt/FTO counter
electrodes have been examined by cyclic voltammetry. 相似文献
10.
《Current Applied Physics》2020,20(9):1041-1048
We report the effect of germanium doping on the active layer of amorphous Zinc–Tin-Oxide (a-ZTO) thin film transistor (TFT). Amorphous thin film samples were prepared by RF magnetron sputtering using single targets composed of Zn2Ge0.05Sn0.95O4 and Zn2SnO4 with variable oxygen contents in the sputtering gases. In comparison with undoped, Ge-doped a-ZTO films exhibited five order of magnitude lower carrier density with a significantly higher Hall-mobility, which might be due to suppressed oxygen vacancies in the a-ZTO lattice since the Ge substituent for the Sn site has relatively higher oxygen affinity. Thus, the bulk and interface trap densities of Ge-doped a-ZTO film were decreased one order of magnitude to 7.047 × 1018 eV−1cm−3 and 3.52 × 1011 eV−1cm−2, respectively. A bottom-gate TFT with the Ge-doped a-ZTO active layer showed considerably improved performance with a reduced SS, positively shifted Vth, and two orders of magnitude increased Ion/Ioff ratio, attributable to the doped Ge ions. 相似文献
11.
X.?Y.?Chen C.?T.?Yip M.?K.?Fung A.?B.?Djuri?i? W.?K.?Chan 《Applied Physics A: Materials Science & Processing》2010,100(1):15-19
GaN nanowires typically exhibit high electron mobility and excellent chemical stability. However, stability of GaN is detrimental
for successful attachment of dye molecules and its application in dye-sensitized solar cells (DSSCs). Here we demonstrate
DSSCs based on GaN/gallium oxide and GaN/TiO
x
core–shell structures, and we show that coating of GaN nanowires with a TiO
x
shell significantly increases dye adsorption and consequently photovoltaic performance. The best cells exhibited short circuit
current density of 1.83 mA/cm2 and power conversion efficiency of 0.44% under AM 1.5 simulated solar illumination. 相似文献
12.
Lee Ming-Kwei Yen Chih-Feng Chiu Shih-Chen 《Applied Physics A: Materials Science & Processing》2011,104(4):1175-1180
The electrical characteristics of thin TiO2 films prepared by metal–organic chemical vapor deposition grown on a p-type InP substrate were studied. For a TiO2 film of 4.7 nm on InP without and with ammonium sulfide treatment, the leakage currents are 8.8×10−2 and 1.1×10−4 A/cm2 at +2 V bias and 1.6×10−1 and 8.3×10−4 A/cm2 at −2 V bias. The lower leakage currents of TiO2 with ammonium sulfide treatment arise from the improvement of interface quality. The dielectric constant and effective oxide
charge number density are 33 and 2.5×1013 cm2, respectively. The lowest mid-gap interface state density is around 7.6×1011 cm−2 eV−1. The equivalent oxide thickness is 0.52 nm. The breakdown electric field increases with decreasing thickness in the range
of 2.5 to 7.6 nm and reaches 9.3 MV/cm at 2.5 nm. 相似文献
13.
Performance of dye-sensitized solar cells (DSSCs) based on TiO2 nanotubes (NTs) filled with TiO2 nanoparticles (NPs) was studied as a function of NT height (h). The NT height was varied in the range of 1.5–7.0 μm, while the NT diameter was kept constant at ~80 nm. The studies showed
that DSSC efficiency, current density, and fill factor linearly increased with h and ranged in 1.76–6.5%, 3.62–13.2 mA/cm2, and 0.66–0.76, respectively, within the h range studied. The electrochemical impedance spectroscopy was also performed to study DSSC electron transport properties.
Based on both photovoltaic and electrochemical impedance spectroscopy data, the results were explained as being due to the
increased dye loading that led to higher light-harvesting efficiency. 相似文献
14.
Deok Kyu Kim Kyeong Min Kim Choon Bae Park 《Applied Physics A: Materials Science & Processing》2010,98(4):913-917
A p-type ZnO thin film was prepared using arsenic diffusion via the ampoule-tube method. This was followed by fabrication
of a ZnO p–n homojunction using n-type ZnO and characterization of the device properties. The ZnO thin film exhibited p-type
characteristics, with a resistivity of 2.19×10−3 Ω cm, a carrier concentration of 1.73×1020/cm3, and a mobility of 26.7 cm2/V s. Secondary ion mass spectrometer analysis confirmed that in- and out-diffusion occurred simultaneously from the external
As source and the GaAs substrate. The device exhibited the rectification characteristics of a typical p–n junction; the forward
voltage at 20 mA was approximately 5.5 V. The reverse-bias leakage current was very low—0.1 mA for −10 V; the breakdown voltage
was −11 V. The ampoule-tube method for fabricating p-type ZnO thin films may be useful in producing ultraviolet ZnO LEDs and
other ZnO-based devices. 相似文献
15.
《Current Applied Physics》2014,14(6):850-855
Transparent and conductive thin films of fluorine doped zinc tin oxide (FZTO) were deposited on glass substrates by radio-frequency (RF) magnetron sputtering using a 30 wt% ZnO with 70 wt% SnO2 ceramic targets. The F-doping was carried out by introducing a mixed gas of pure Ar, CF4, and O2 forming gas into the sputtering chamber while sputtering ZTO target. The effect of annealing temperature on the structural, electrical and optical performances of FZTO thin films has been studied. FZTO thin film annealed at 600 °C shows the decrease in resistivity 5.47 × 10−3 Ω cm, carrier concentration ∼1019 cm−3, mobility ∼20 cm2 V−1 s−1 and an increase in optical band gap from 3.41 to 3.60 eV with increasing the annealing temperatures which is well explained by Burstein–Moss effect. The optical transmittance of FZTO films was higher than 80% in all specimens. Work function (ϕ) of the FZTO films increase from 3.80 eV to 4.10 eV through annealing and are largely dependent on the amounts of incorporated F. FZTO is a possible potential transparent conducting oxide (TCO) alternative for application in optoelectronics. 相似文献
16.
Peng Sun Haibin Yang Wuyou Fu Minghui Li Yanyan Zhang 《Applied Surface Science》2010,256(10):3170-9643
Nanostructured titanium dioxide (TiO2) thin films have been prepared on metal substrates using a facile layer-by-layer dip-coating method. The phase structure and morphologies of preparing samples were characterized by means of X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The results confirm that films are highly crystalline anatase TiO2 and free from other phases of titanium dioxide. Scanning electron microscopy (SEM) shows that the nanoparticles are sintered together to form a compact structure. The electrical properties of samples were investigated by cutternt-voltage analysis, the result indicates that a rectifying junction between the nanocrystalline TiO2 film and metal substrate was formed. The photoelectrochemical characteristics recorded under 1.5 AM illumination indicates that the as-fabricated thin film electrode possesses the highest photocurrent density at 450 °C, which is 1.75 mA/cm2 at 0 V vs. Ag/AgCl. 相似文献
17.
Sava? S?nmezo?lu Güven ?ankaya Necmi Serin 《Applied Physics A: Materials Science & Processing》2012,107(1):233-241
Nanostructured TiO2 thin films were deposited on quartz glass at room temperature by sol–gel dip coating method. The effects of annealing temperature
between 200∘C to 1100∘C were investigated on the structural, morphological, and optical properties of these films. The X-ray diffraction results
showed that nanostructured TiO2 thin film annealed at between 200∘C to 600∘C was amorphous transformed into the anatase phase at 700∘C, and further into rutile phase at 1000∘C. The crystallite size of TiO2 thin films was increased with increasing annealing temperature. From atomic force microscopy images it was confirmed that
the microstructure of annealed thin films changed from column to nubbly. Besides, surface roughness of the thin films increases
from 1.82 to 5.20 nm, and at the same time, average grain size as well grows up from about 39 to 313 nm with increase of the
annealing temperature. The transmittance of the thin films annealed at 1000 and 1100∘C was reduced significantly in the wavelength range of about 300–700 nm due to the change of crystallite phase. Refractive
index and optical high dielectric constant of the n-TiO2 thin films were increased with increasing annealing temperature, and the film thickness and the optical band gap of nanostructured
TiO2 thin films were decreased. 相似文献
18.
A novel sol-gel/laser-induced technique (SGLIT) has been developed to form nanocrystalline titanium dioxide (TiO2) based thin films with an improved antibacterial performance. TiO2 precursor films loaded with W+6 and Ag+2 ions (W–TiO2, Ag–TiO2) were prepared separately by sol-gel method and spin-coated on microscopic glass slides. As-dried films were subjected to
KrF excimer laser pulses at optimized parameters to generate mesoporous anatase and rutile phases at room temperature. The
anatase phase was obtained after irradiation with 10 laser pulses only at 75–85 mJ/cm2 fluence in W–TiO2 films. However, higher number of laser pulses and higher W+6 content favored the formation of rutile. Whereas Ag–TiO2 films exhibited anatase up to 200 laser pulses at the same fluence. The films were characterized by using XRD, FEG-SEM, TEM
and UV-Vis spectrophotometer to investigate the crystallographic structure, phase transformation, surface morphology, film
thickness and the optical properties. A crystallite size of approximately 20 nm was achieved from the anatase prepared by
SGLIT. The films exhibited an enhanced antibacterial function against E-Coli cells under the UV excitation. 相似文献
19.
Yuechun Fu Xuefei Li Yunyun Wang Huan He Xiaoming Shen 《Applied Physics A: Materials Science & Processing》2012,106(4):937-940
Cubic AlN films were successfully deposited on TiN buffered Si (100) substrates by a laser molecular beam epitaxy (LMBE) technique,
and their crystal structure and optical and electrical properties were studied. The results indicate that cubic AlN films
show the NaCl-type structure with a (200) preferred orientation, and the lattice parameter is determined to be 0.4027 nm.
The Fourier transform infrared (FTIR) pattern of the cubic AlN film displays sharp absorption peaks at 668 cm−1 and 951 cm−1, corresponding to the transverse and longitudinal optical vibration modes. Ellipsometric measurements evidence a refractive
index of 1.66–1.71 and an extinction coefficient of about zero for the cubic AlN film in the visible range. Capacitance–voltage
(C–V) traces of the metal–insulator–semiconductor (MIS) device exhibit that the cubic AlN film has a dielectric constant of 8.1,
and hysteresis in the C–V traces indicates a significant number of charge traps in the film. 相似文献
20.
《Current Applied Physics》2015,15(2):94-97
Hf–Sn–Zn–O (HTZO) thin films were prepared on SiO2/SiNx substrates at room temperature by the direct current (DC) magnetron sputtering of Hf-doped Sn–Zn–O targets. The characteristics of films with different amounts of Hf were analyzed. Amorphous HTZO films were obtained by increasing the Hf content, while polycrystalline films have not shown with Hf doping. With the proper Hf concentration in the HTZO films (∼2.0 atomic % Hf/(Hf + Sn + Zn + O)), HTZO films demonstrated good performance as an oxide semiconductor channel material in thin film transistors (TFTs) with a field effect mobility (μFE) of 10.9 cm2V−1 s−1, an on/off current ratio of 109, and a subthreshold voltage swing of 0.71 V/decade. 相似文献