Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Pharmacol Res ; 208: 107349, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39151679

RESUMEN

In future regenerative medicine, far-infrared radiation (FIR) may be an essential component of optical therapy. Many studies have confirmed or validated the efficacy and safety of FIR in various diseases, benefiting from new insights into FIR mechanisms and the excellent performance of many applications. However, the lack of consensus on the biological effects and therapeutic parameters of FIR limits its practical applications in the clinic. In this review, the definition, characteristics, and underlying principles of the FIR are systematically illustrated. We outline the therapeutic parameters of FIR, including the wavelength range, power density, irradiation time, and distance. In addition, the biological effects, potential molecular mechanisms, and preclinical and clinical applications of FIR are discussed. Furthermore, the future development and applications of FIR are described in this review. By applying optimal therapeutic parameters, FIR can influence various cells, animal models, and patients, eliciting diverse underlying mechanisms and offering therapeutic potential for many diseases. FIR could represent a superior alternative with broad prospects for application in future regenerative medicine.


Asunto(s)
Rayos Infrarrojos , Medicina Regenerativa , Medicina Regenerativa/métodos , Medicina Regenerativa/tendencias , Humanos , Animales , Rayos Infrarrojos/uso terapéutico
2.
Body Image ; 50: 101739, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38820800

RESUMEN

In the present study, we explored the factor structure and psychometric properties of the Mandarin Chinese BAS-2 among adolescents residing in the Chinese mainland. Exploratory factor analysis in Study 1 (N = 790; 396 girls, 394 boys) supported the unidimensionality of the Mandarin Chinese BAS-2 among Chinese adolescents. Internal consistency reliability was upheld via McDonald's omega. Convergent validity was supported by its moderate-to-strong relationships with body satisfaction, functionality satisfaction, self-esteem, life satisfaction, positive affect, and negative affect, while its small-to-moderate correlation with social desirability provided somewhat weaker discriminant validity support. Criterion-related validity was upheld by its inverse correlation with eating disorder symptomatology and positive correlation with intuitive eating. It explained unique variance in self-esteem (for girls and boys), eating disorder symptomatology (for girls), and intuitive eating (for boys) beyond age, body satisfaction, and functionality satisfaction, providing incremental validity evidence. A subsample of 134 girls and 114 boys completed the Mandarin Chinese BAS-2 again after three months, and test-retest reliability was upheld. The confirmatory factor analysis in Study 2 (N = 337; 192 girls, 145 boys) replicated the unidimensional structure and supported measurement invariance across gender. Collectively, the present study supported the unidimensionality, reliability, and validity of the Mandarin Chinese BAS-2's scores among Chinese adolescents.


Asunto(s)
Imagen Corporal , Satisfacción Personal , Psicometría , Autoimagen , Humanos , Femenino , Masculino , Adolescente , Reproducibilidad de los Resultados , Imagen Corporal/psicología , China , Encuestas y Cuestionarios , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Trastornos de Alimentación y de la Ingestión de Alimentos/etnología , Análisis Factorial , Niño , Pueblo Asiatico/psicología
3.
Nanomaterials (Basel) ; 14(8)2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38668184

RESUMEN

It is usually difficult to realize high mobility together with a low threshold voltage and good stability for amorphous oxide thin-film transistors (TFTs). In addition, a low fabrication temperature is preferred in terms of enhancing compatibility with the back end of line of the device. In this study, α-IGZO TFTs were prepared by high-power impulse magnetron sputtering (HiPIMS) at room temperature. The channel was prepared under a two-step deposition pressure process to modulate its electrical properties. X-ray photoelectron spectra revealed that the front-channel has a lower Ga content and a higher oxygen vacancy concentration than the back-channel. This process has the advantage of balancing high mobility and a low threshold voltage of the TFT when compared with a conventional homogeneous channel. It also has a simpler fabrication process than that of a dual active layer comprising heterogeneous materials. The HiPIMS process has the advantage of being a low temperature process for oxide TFTs.

4.
Opt Express ; 31(20): 33732-33740, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37859146

RESUMEN

Atomic layer deposited Al2O3 films are incorporated into miniature light emitting diodes (mini-LEDs) as an internal moisture barrier layer. The experimental results show that the water vapor transmission rate reaches ≤10-4 g/m2/day when the Al2O3 thickness is ≥40 nm. The mini-LED with a 40 nm-thick Al2O3 layer shows negligible degradation after 1000 h of 85°C/85% relative humidity testing, whereas the device without an Al2O3 layer fails after only 500 h due to delamination occurring at the GaN surface. Current-voltage characteristics of the device without an Al2O3 moisture barrier layer indicate an increase in series resistance and ideality factor. This study provides a simple, light-weighting method to have a satisfactory encapsulation function for miniature LEDs.

5.
Cell Rep ; 42(9): 113134, 2023 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-37708029

RESUMEN

The organization and dynamics of chromatin fiber play crucial roles in regulating DNA accessibility for gene expression. Here we combine cryoelectron tomography (cryo-ET), sub-volume averaging, and 3D segmentation to visualize the in vitro and in vivo chromatin fibers folding by linker histone. We discover that an increased nucleosome repeat length and prolonged fiber length do not change the two-start helical architecture in reconstituted chromatin of homogeneous composition. Additionally, an isolated chromatin fiber with heterogeneous composition was observed, which includes short-range regions compatible with two-start helix. In vivo, sub-volume averaging reveals similar subunits of two-start helical architecture in transcriptionally inactive chromatin in frog erythrocyte nuclei. Strikingly, unambiguous DNA trajectories that displayed a zigzag pattern universally between alternate N/N+2 nucleosomes were further determined by cryo-ET with voltage phase plate. Therefore, these structural similarities suggest a general folding mode of chromatin induced by linker histone, and heterogeneous compositions mainly affect local conformation rather than changing the overall architecture.


Asunto(s)
Cromatina , Histonas , Histonas/metabolismo , Modelos Moleculares , Nucleosomas , ADN/metabolismo
6.
Int J Mol Sci ; 23(24)2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36555844

RESUMEN

In recent years, the application of (In, Al, Ga)N materials in photovoltaic devices has attracted much attention. Like InGaN, it is a direct band gap material with high absorption at the band edge, suitable for high efficiency photovoltaic devices. Nonetheless, it is important to deposit high-quality GaN material as a foundation. Plasma-enhanced atomic layer deposition (PEALD) combines the advantages of the ALD process with the use of plasma and is often used to deposit thin films with different needs. However, residual oxygen during growth has always been an unavoidable issue affecting the quality of the resulting film, especially in growing gallium nitride (GaN) films. In this study, the NH3-containing plasma was used to capture the oxygen absorbed on the growing surface to improve the quality of GaN films. By diagnosing the plasma, NH2, NH, and H radicals controlled by the plasma power has a strong influence not only on the oxygen content in growing GaN films but also on the growth rate, crystallinity, and surface roughness. The NH and NH2 radicals contribute to the growth of GaN films while the H radicals selectively dissociate Ga-OH bonds on the film surface and etch the grown films. At high plasma power, the GaN film with the lowest Ga-O bond ratio has a saturated growth rate, a better crystallinity, a rougher surface, and a lower bandgap. In addition, the deposition mechanism of GaN thin films prepared with a trimethylgallium metal source and NH3/Ar plasma PEALD involving oxygen participation or not is also discussed in the study.


Asunto(s)
Amoníaco , Películas Cinematográficas , Oxígeno , Plasma
7.
Molecules ; 27(23)2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36500217

RESUMEN

Gallium nitride (GaN) is a wide bandgap semiconductor with remarkable chemical and thermal stability, making it a competitive candidate for a variety of optoelectronic applications. In this study, GaN films are grown using a plasma-enhanced atomic layer deposition (PEALD) with trimethylgallium (TMG) and NH3 plasma. The effect of substrate temperature on growth mechanism and properties of the PEALD GaN films is systematically studied. The experimental results show that the self-limiting surface chemical reactions occur in the substrate temperature range of 250-350 °C. The substrate temperature strongly affects the crystalline structure, which is nearly amorphous at below 250 °C, with (100) as the major phase at below 400 °C, and (002) dominated at higher temperatures. The X-ray photoelectron spectroscopy spectra reveals the unintentional oxygen incorporation into the films in the forms of Ga2O3 and Ga-OH. The amount of Ga-O component decreases, whereas the Ga-Ga component rapidly increases at 400 and 450 °C, due to the decomposition of TMG. The substrate temperature of 350 °C with the highest amount of Ga-N bonds is, therefore, considered the optimum substrate temperature. This study is helpful for improving the quality of PEALD GaN films.


Asunto(s)
Plasma , Semiconductores , Oxígeno , Espectroscopía de Fotoelectrones
8.
Front Comput Neurosci ; 16: 1047954, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36405786

RESUMEN

Tic is a combination of a series of static facial and limb movements over a certain period in some children. However, due to the scarcity of tic disorder (TD) datasets, the existing work on tic recognition using deep learning does not work well. It is that spatial complexity and time-domain variability directly affect the accuracy of tic recognition. How to extract effective visual information for temporal and spatial expression and classification of tic movement is the key of tic recognition. We designed the slow-fast and light-efficient channel attention network (SFLCA-Net) to identify tic action. The whole network adopted two fast and slow branch subnetworks, and light-efficient channel attention (LCA) module, which was designed to solve the problem of insufficient complementarity of spatial-temporal channel information. The SFLCA-Net is verified on our TD dataset and the experimental results demonstrate the effectiveness of our method.

9.
Nanomaterials (Basel) ; 12(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36364666

RESUMEN

Hafnium oxide (HfO2) thin film has remarkable physical and chemical properties, which makes it useful for a variety of applications. In this work, HfO2 films were prepared on silicon through plasma enhanced atomic layer deposition (PEALD) at various substrate temperatures. The growth per cycle, structural, morphology and crystalline properties of HfO2 films were measured by spectroscopic ellipsometer, grazing-incidence X-ray diffraction (GIXRD), X-ray reflectivity (XRR), field-emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy. The substrate temperature dependent electrical properties of PEALD-HfO2 films were obtained by capacitance-voltage and current-voltage measurements. GIXRD patterns and XRR investigations show that increasing the substrate temperature improved the crystallinity and density of HfO2 films. The crystallinity of HfO2 films has a major effect on electrical properties of the films. HfO2 thin film deposited at 300 °C possesses the highest dielectric constant and breakdown electric field.

10.
Nanomaterials (Basel) ; 12(16)2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-36014724

RESUMEN

The promising functional tin oxide (SnOx) has attracted tremendous attention due to its transparent and conductive properties. The stoichiometric composition of SnOx can be described as common n-type SnO2 and p-type Sn3O4. In this study, the functional SnOx films were prepared successfully by plasma-enhanced atomic layer deposition (PEALD) at different substrate temperatures from 100 to 400 °C. The experimental results involving optical, structural, chemical, and electrical properties and morphologies are discussed. The SnO2 and oxygen-deficient Sn3O4 phases coexisting in PEALD SnOx films were found. The PEALD SnOx films are composed of intrinsic oxygen vacancies with O-Sn4+ bonds and then transformed into a crystalline SnO2 phase with increased substrate temperature, revealing a direct 3.5−4.0 eV band gap and 1.9−2.1 refractive index. Lower (<150 °C) and higher (>300 °C) substrate temperatures can cause precursor condensation and desorption, respectively, resulting in reduced film qualities. The proper composition ratio of O to Sn in PEALD SnOx films near an estimated 1.74 suggests the highest mobility of 12.89 cm2 V−1 s−1 at 300 °C.

11.
Nanomaterials (Basel) ; 12(12)2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35745334

RESUMEN

Indium tin oxide (ITO) thin films were prepared by high power impulse magnetron sputtering (HiPIMS) and annealed in hydrogen-containing forming gas to reduce the film resistivity. The film resistivity reduces by nearly an order of magnitude from 5.6 × 10-3 Ω·cm for the as-deposited film to the lowest value of 6.7 × 10-4 Ω·cm after annealed at 700 °C for 40 min. The role of hydrogen (H) in changing the film properties was explored and discussed in a large temperature range (300-800 °C). When annealed at a low temperature of 300-500 °C, the incorporated H atoms occupied the oxygen sites (Ho), acting as shallow donors that contribute to the increase of carrier concentration, leading to the decrease of film resistivity. When annealed at an intermediate temperature of 500-700 °C, the Ho defects are thermally unstable and decay upon annealing, leading to the reduction of carrier concentration. However, the film resistivity keeps decreasing due to the increase in carrier mobility. Meanwhile, some locally distributed metallic clusters formed due to the reduction effect of H2. When annealed at a high temperature of 700-800 °C, the metal oxide film is severely reduced and transforms to gaseous metal hydride, leading to the dramatic reduction of film thickness and carrier mobility at 750 °C and vanish of the film at 800 °C.

12.
Nanomaterials (Basel) ; 12(9)2022 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-35564219

RESUMEN

Amorphous Gallium oxide (Ga2O3) thin films were grown by plasma-enhanced atomic layer deposition using O2 plasma as reactant and trimethylgallium as a gallium source. The growth rate of the Ga2O3 films was about 0.6 Å/cycle and was acquired at a temperature ranging from 80 to 250 °C. The investigation of transmittance and the adsorption edge of Ga2O3 films prepared on sapphire substrates showed that the band gap energy gradually decreases from 5.04 to 4.76 eV with the increasing temperature. X-ray photoelectron spectroscopy (XPS) analysis indicated that all the Ga2O3 thin films showed a good stoichiometric ratio, and the atomic ratio of Ga/O was close to 0.7. According to XPS analysis, the proportion of Ga3+ and lattice oxygen increases with the increase in temperature resulting in denser films. By analyzing the film density from X-ray reflectivity and by a refractive index curve, it was found that the higher temperature, the denser the film. Atomic force microscopic analysis showed that the surface roughness values increased from 0.091 to 0.187 nm with the increasing substrate temperature. X-ray diffraction and transmission electron microscopy investigation showed that Ga2O3 films grown at temperatures from 80 to 200 °C were amorphous, and the Ga2O3 film grown at 250 °C was slightly crystalline with some nanocrystalline structures.

13.
J Econ Entomol ; 115(1): 250-258, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-34897481

RESUMEN

A glue paste lining is a traditional conservation treatment used to reinforce the aged canvas of oil paintings. Several insect infestation cases concerning glue paste-lined oil paintings have been reported around the world, particularly in European countries. In 2008, Chimei Museum, a private museum located in Tainan, Taiwan, was affected by a severe beetle infestation of oil paintings. To confirm the infesting insects and to quantify the damage pattern for further development of control and monitoring methods, three severely damaged paintings were examined along with the restoration procedure. A total of four insect species were collected. The drugstore beetle, Stegobium paniceum (L.) (Coleopter: Ptinidae), was the primary pest found in all three paintings investigated and was identified based on morphological and genetic data. Thrips and booklice were considered secondary pests, and a Pteromalid wasp was speculated to have a parasitic relationship with the drugstore beetle. Drugstore beetle larvae mainly bored into the glue paste layer and original canvas and required only 5.94 ± 1.38 mm3 of feed to grow from egg to pupa. Their bores were not evenly distributed, and most of them were found in the shaded area covered by the stretcher and outer frame. The body length of drugstore beetles varied, ranging from 1.67 to 2.75 mm, which may explain the various sizes of exit holes on gummed tape surrounding the frame. Detailed and quantified information on drugstore beetle's pattern of damage provided in this study will be beneficial for further developing conservation practices and inspection methods.


Asunto(s)
Escarabajos , Pinturas , Avispas , Animales , Europa (Continente) , Pupa
14.
ACS Omega ; 6(43): 29149-29156, 2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34746603

RESUMEN

It is generally known that a layer of amorphous silicon oxide (SiO2) naturally exists on the surface of silicon, resulting in the growth of gallium oxide (Ga2O3) that is no longer affected by substrate crystallinity during sputtering. This work highlights the formation energy between the native amorphous nano-oxide film formed on the Si substrate and monoclinic ß-Ga2O3 dominating the preferred orientation prepared for deep ultraviolet photodetectors. The latter were deposited on p-type silicon (p-Si) with (111) orientation using radio frequency sputtering at 600 °C and post rapid thermal annealing (RTA). The X-ray diffraction (XRD) results indicate both as-deposited and postannealing films with the (400) preferred orientation for a layer thickness of 100 nm. However, slight random orientation with the amorphous structure is mixed in the preferred one for the as-deposited film with a thickness of 200 nm and reduced after being annealed at 800 °C, which is observed by XRD and transmission electron microscopy. Meanwhile, thermal-induced massive twin boundaries (TBs) and stacking faults (SFs) were generated when annealed at 1000 °C, owing to the relaxation of lattice strain by the coherent interface. The interfacial bonding energy per unit area (E i) between ß-Ga2O3 films with various facets ((001), (010), (100), and (2̅01)) and amorphous SiO2 was calculated using density functional theory. The E i of ß-Ga2O3 (100)/SiO2 reveals the highest value (0.289 eV/Å2), which is consistent with the (100) preferred orientation of deposited films. The (100) preferred orientation is the driving force for TBs and SFs. The discrimination of responsivities and the photo/dark current contrast ratio (I ph/I dark) are inversely proportional to the amorphous structure, grain boundaries, TBs, and SFs. Therefore, optimum metal-semiconductor-metal photodetector performance is achieved for RTA-treated samples at 800 °C with an I ph/I dark of 3.91 × 102 and a responsivity of 0.702 A/W (λpeak = 230 nm) at 5 V bias for a 200 nm thin film.

15.
Nanomaterials (Basel) ; 11(6)2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-34200248

RESUMEN

Tantalum (Ta)-doped titanium oxide (TiO2) thin films are grown by plasma enhanced atomic layer deposition (PEALD), and used as both an electron transport layer and hole blocking compact layer of perovskite solar cells. The metal precursors of tantalum ethoxide and titanium isopropoxide are simultaneously injected into the deposition chamber. The Ta content is controlled by the temperature of the metal precursors. The experimental results show that the Ta incorporation introduces oxygen vacancies defects, accompanied by the reduced crystallinity and optical band gap. The PEALD Ta-doped films show a resistivity three orders of magnitude lower than undoped TiO2, even at a low Ta content (0.8-0.95 at.%). The ultraviolet photoelectron spectroscopy spectra reveal that Ta incorporation leads to a down shift of valance band and conduction positions, and this is helpful for the applications involving band alignment engineering. Finally, the perovskite solar cell with Ta-doped TiO2 electron transport layer demonstrates significantly improved fill factor and conversion efficiency as compared to that with the undoped TiO2 layer.

16.
Nanomaterials (Basel) ; 11(5)2021 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-33947065

RESUMEN

In this study, silicon oxide (SiO2) films were deposited by remote plasma atomic layer deposition with Bis(diethylamino)silane (BDEAS) and an oxygen/argon mixture as the precursors. Oxygen plasma powers play a key role in the quality of SiO2 films. Post-annealing was performed in the air at different temperatures for 1 h. The effects of oxygen plasma powers from 1000 W to 3000 W on the properties of the SiO2 thin films were investigated. The experimental results demonstrated that the SiO2 thin film growth per cycle was greatly affected by the O2 plasma power. Atomic force microscope (AFM) and conductive AFM tests show that the surface of the SiO2 thin films, with different O2 plasma powers, is relatively smooth and the films all present favorable insulation properties. The water contact angle (WCA) of the SiO2 thin film deposited at the power of 1500 W is higher than that of other WCAs of SiO2 films deposited at other plasma powers, indicating that it is less hydrophilic. This phenomenon is more likely to be associated with a smaller bonding energy, which is consistent with the result obtained by Fourier transformation infrared spectroscopy. In addition, the influence of post-annealing temperature on the quality of the SiO2 thin films was also investigated. As the annealing temperature increases, the SiO2 thin film becomes denser, leading to a higher refractive index and a lower etch rate.

17.
Nanomaterials (Basel) ; 11(4)2021 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-33920231

RESUMEN

Indium oxide (In2O3) film has excellent optical and electrical properties, which makes it useful for a multitude of applications. The preparation of In2O3 film via atomic layer deposition (ALD) method remains an issue as most of the available In-precursors are inactive and thermally unstable. In this work, In2O3 film was prepared by ALD using a remote O2 plasma as oxidant, which provides highly reactive oxygen radicals, and hence significantly enhancing the film growth. The substrate temperature that determines the adsorption state on the substrate and reaction energy of the precursor was investigated. At low substrate temperature (100-150 °C), the ratio of chemically adsorbed precursors is low, leading to a low growth rate and amorphous structure of the films. An amorphous-to-crystalline transition was observed at 150-200 °C. An ALD window with self-limiting reaction and a reasonable film growth rate was observed in the intermediate temperature range of 225-275 °C. At high substrate temperature (300-350 °C), the film growth rate further increases due to the decomposition of the precursors. The resulting film exhibits a rough surface which consists of coarse grains and obvious grain boundaries. The growth mode and properties of the In2O3 films prepared by plasma-enhanced ALD can be efficiently tuned by varying the substrate temperature.

18.
Materials (Basel) ; 14(3)2021 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-33540775

RESUMEN

In this study, the effect of radical intensity on the deposition mechanism, optical, and electrical properties of tin oxide (SnO2) thin films is investigated. The SnO2 thin films are prepared by plasma-enhanced atomic layer deposition with different plasma power from 1000 to 3000 W. The experimental results show that plasma contains different amount of argon radicals (Ar*) and oxygen radicals (O*) with the increased power. The three deposition mechanisms are indicated by the variation of Ar* and O* intensities evidenced by optical emission spectroscopy. The adequate intensities of Ar* and O* are obtained by the power of 1500 W, inducing the highest oxygen vacancies (OV) ratio, the narrowest band gap, and the densest film structure. The refractive index and optical loss increase with the plasma power, possibly owing to the increased film density. According to the Hall effect measurement results, the improved plasma power from 1000 to 1500 W enhances the carrier concentration due to the enlargement of OV ratio, while the plasma powers higher than 1500 W further cause the removal of OV and the significant bombardment from Ar*, leading to the increase of resistivity.

19.
Molecules ; 25(21)2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-33143026

RESUMEN

In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.


Asunto(s)
Aluminio/química , Membranas Artificiales , Oxígeno/química , Óxido de Zinc/química , Propiedades de Superficie , Difracción de Rayos X
20.
Materials (Basel) ; 13(18)2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32899677

RESUMEN

Zinc oxide (ZnO) has drawn much attention due to its excellent optical and electrical properties. In this study, ZnO film was prepared by a high-deposition-rate spatial atomic layer deposition (ALD) and subjected to a post-annealing process to suppress the intrinsic defects and improve the crystallinity and film properties. The results show that the film thickness increases with annealing temperature owing to the increment of oxide layer caused by the suppression of oxygen vacancy defects as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra. The film transmittance is seldom influenced by annealing. The refractive index increases with annealing temperature at 300-700 °C, possibly due to higher density and crystallinity of the film. The band gap decreases after annealing, which should be ascribed to the decrease in carrier concentration according to Burstein-Moss model. The carrier concentration decreases with increasing annealing temperature at 300-700 °C since the oxygen vacancy defects are suppressed, then it increases at 800 °C possibly due to the out-diffusion of oxygen atoms from the film. Meanwhile, the carrier mobility increases with temperature due to higher crystallinity and larger crystallite size. The film resistivity increases at 300-700 °C then decreases at 800 °C, which should be ascribed primarily to the variation of carrier concentration.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...