共查询到20条相似文献,搜索用时 15 毫秒
1.
nc-SiC/SiO_2镶嵌薄膜材料的制备、结构和发光特性 总被引:1,自引:0,他引:1
采用二氧化硅/碳化硅复合靶,用射频磁控共溅射技术和后高温退火的方法在Si(111)衬底上制备了碳化硅纳米颗粒/二氧化硅基质(nc-SiC/SiO2)镶嵌结构薄膜材料。用X射线衍射(XRD),傅里叶红外吸收(FTIR),扫描电子显微镜(SEM)和光致发光(PL)实验分析了薄膜的微结构以及光致发光特性。实验结果表明,样品薄膜经高温退火后,部分无定形SiC发生晶化,形成β-SiC纳米颗粒而较均匀地镶嵌在SiO2基质中。以280nm波长光激发薄膜表面,有较强的365nm的紫外光发射以及458nm和490nm处的蓝光发射,其发光强度随退火温度的升高显著增强,发光归结为薄膜中与Si—O相关的缺陷形成的发光中心。 相似文献
2.
SiC/SiO_2镶嵌结构薄膜光致发光特性研究 总被引:2,自引:0,他引:2
采用 SiC/SiO_2复合靶,用射频磁控共溅射技术和高温退火的方法制备了 SiC/SiO_2纳米镶嵌结构复合薄膜,并应用傅里叶红外吸收(FTIR),X 射线衍射(XRD),扫描电镜(SEM)和光致发光(PL)实验分析了薄膜的结构、表面形貌以及光致发光性能。结果表明,样品经高温退火后在 SiO_2基质中有 SiC 纳米颗粒形成。以 280 nm 波长光激发样品薄膜表面,显示出较强的 365 nm 的紫外光发射以及 458 nm 和 490 nm 处的蓝光发射,其发光强度随退火温度从 800℃升高至 1 050℃而增强。其发光归结为薄膜中与 Si-O 相关的缺陷形成的发光中心。 相似文献
3.
Cong-mian Zhen Jin-juan Zhang Xiao-qiang Wang Yong-jin Zhang Cheng-fu Pan Deng-lu Hou 《光电子快报》2008,4(6):429-432
SiC granule films were fabricated onto porous glass substrate by RF-magnetron sputtering. Photoluminescence (PL) measurements show that there are light emissions at three different wavelengths. Ultraviolet emission peaked at 360 nm originated from the band-band transmission of SiC nanoparticles with relatively small size. The 370 nm light emission was due to the luminescence of the nano-skeletons of porous glass that was formed during the etching of the glass substrate. The blue emission at about 460 nm was associated with the recombination of the excited electron and O-deficient defects appeared at the interface between SiC nanoparticles and the porous glass. Furthermore, the optimal PL performance was obtained when SiC deposited time was I h and the glass substrate was etched for 20 min in the annealing sample (450 ℃). 相似文献
4.
用ECRCVD法制备的纳米碳化硅薄膜及其室温下的强光发射 总被引:2,自引:0,他引:2
用电子回旋共振化学气相沉积(ECRCVD)方法制备了纳米碳化硅薄膜.实验中发现:在高氢稀释反应气体和高微波功率条件下,可以得到结构上具有纳米碳化硅晶粒镶嵌在碳化硅无序网络中的薄膜.用高分辩透射电子显微镜、傅里叶红外吸收谱、Raman散射和X射线光电子谱等分析手段对薄膜的结构进行了分析.在室温条件下,薄膜能够发出强烈的短波长可见光,发光峰位于能量为2.64eV处.瞬态光谱研究表明样品的光致发光寿命为纳秒数量级,表现出直接跃迁复合的特征.这种材料有希望在大面积平面显示器件中得到应用. 相似文献
5.
热丝化学气相沉积法低温制备纳米晶态碳化硅薄膜 总被引:1,自引:1,他引:0
采用热丝化学气相沉积(HFCVD)技术以甲烷(CH4)和硅烷(SiH4)作为源反应气体在Si(111)衬底上合成了纳米晶态SiC薄膜。通过X射线衍射(XRD)、扫描电镜(SEM)、高分辨透射电镜(HRTEM)以及光致发光(PL)检测技术对薄膜的晶体结构、表面形貌和PL特性进行了分析和表征。结果表明,在较低的衬底温度下所沉积的薄膜是由镶嵌于非晶SiC网络中的晶态纳米SiC构成。纳米晶粒平均尺寸约为6nm。室温下用HeCr激光激发样品,观到薄膜发出波长位于400~550nm范围内可见光辐射。 相似文献
6.
《Solid-state electronics》2006,50(7-8):1189-1193
Amorphous silicon carbide films were deposited by RF sputtering technique using a SiC target. These films were annealed in dry oxygen ambient in the temperature range of 400–700 °C. Subsequently the films were characterized using X-ray photoelectron spectroscopy (XPS) to investigate the chemical composition at each annealing temperature. XPS indicated that increasing the anneal temperature results in a decrease in SiC phase, and an increase in SiOx. Surface morphology of the oxidized films was characterized using atomic force microscope. Optical absorption studies indicated blue shifting effects as the annealing temperature was increased. 相似文献
7.
Ruidong Xia Wen‐Yong Lai Peter A. Levermore Wei Huang Donal D. C. Bradley 《Advanced functional materials》2009,19(17):2844-2850
Here, a detailed characterization of the optical gain properties of sky‐blue‐light‐emitting pyrene‐cored 9,9‐dialkylfluorene starbursts is reported; it is shown that these materials possess encouragingly low laser thresholds and relatively high thermal and environmental stability. The materials exhibit high solid‐state photoluminescence (PL) quantum efficiencies (>90%) and near‐single‐exponential PL decay transients with excited state lifetimes of ~1.4 ns. The thin‐film slab waveguide amplified spontaneous emission (ASE)‐measured net gain reaches 75–78 cm?1. The ASE threshold energy is found to remain unaffected by heating at temperatures up to 130 °C, 40 to 50 °C above Tg. The ASE remained observable for annealing temperatures up to 170 or 200 °C. 1D distributed feedback lasers with 75% fill factor and 320 nm period show optical pumping thresholds down to 38–65 Wcm?2, laser slope efficiencies up to 3.9%, and wavelength tuning ranges of ~40 nm around 471–512 nm. In addition, these lasers have relatively long operational lifetimes, with N1/2 ≥ 1.1 × 105 pulses for unencapsulated devices operated at ten times threshold in air. 相似文献
8.
SiC semiconductor-on-insulator (SOI) structures have been investigated as substrates for the growth of GaN films. The SiC
SOI was obtained through the conversion of Si SOI wafers by reaction with propane and H2. (111) SiC SOI have been produced by this carbonization process at temperatures ranging from 1200 to 1300°C. X-ray diffraction
(XRD) and infrared spectroscopy (FTIR) are used to chart the conversion of the Si layer to SiC. Under our conditions, growth
time of 3 min at 1250°C is sufficient to completely convert a 1000? layer. XRD of the SiC SOI reveals a single SiC peak at
2θ = 35.7° corresponding to the (111) reflection, with a corrected full width at half-maximum (FWHM) of ~590±90 arc-sec. Infrared
spectroscopy of SiC SOI structures obtained under optimum carboniza-tion conditions exhibited a sharp absorption peak produced
by the Si-C bond at 795 cm−1, with FWHM of ∼ 20–25 cm−1. Metalorganic CVD growth of GaN on the (111) SiC SOI was carried out with trimethylgallium and NH3. The growth of a thin (≤200?), low temperature (500°C) GaN buffer layer was followed by the growth of a thick (∼2 μm) layer
at 1050°C. Optimum surface morphology was obtained for zero buffer layer. XRD indicates highly oriented hexagonal GaN, with
FWHM of the (0002) peak of ~360±90 arc-sec. Under high power excitation, the 300°K photoluminescence (PL) spectrum of GaN
films exhibits a strong near band-edge peak (at λp~371 nm, with FWHM = 100–150 meV) and very weak yellow emission. Under low power excitation, the 370 nm PL emission from the
GaN/SiC SOI structure increases rapidly with SiC carbonization temperature, while the yellow band (∼550–620 nm) correspondingly
decreases. 相似文献
9.
Effect of Temperature on Structural and Morphologic Properties of ZnO Films Annealed in Ammonia Ambient 总被引:3,自引:0,他引:3
Shoubin Xue Huizhao Zhuang Chengshan Xue Lijun Hu Baoli Li Shiying Zhang 《Journal of Electronic Materials》2007,36(4):502-506
ZnO thin films were prepared on Si(111) substrates by pulsed laser deposition (PLD). Then, the samples were annealed at different
temperatures in NH3 ambient and their properties were investigated particularly as a function of annealing temperature. The structure, morphology,
and optical properties of ZnO films were studied by x-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR),
scanning electron microscope (SEM), and photoluminescence (PL). The results show that the increase of annealing temperature
makes for the improvement in the crystal quality and surface morphology below the temperature of 650°C. However, when the
annealing temperature is above 650°C, the ZnO films will volatilize and, especially at 750°C, ZnO will volatilize completely. 相似文献
10.
ZnS:Na thin films with (111) preferred orientation were deposited on glass substrates by vacuum evaporation method. The as-prepared films were annealed in flowing argon at 400--500 ℃ to improve the film crystallinity and electrically activate the dopants. The structural, optical and electrical properties of ZnS:Na films are investigated by X-ray diffrac- tion (XRD), photoluminescence (PL), optical transmittance measurements and the four-point probe method. Results show that the as-prepared ZnS:Na films are amorphous, and exhibit (111) preferred orientation after annealing at 400 --500 ℃. The PL emissions at 414 nm and 439 nm are enhanced due to the increase of the intrinsic defects induced by the thermal annealing. However, all the samoles exhibit high resistivitv due to the heavy self-compensation. 相似文献
11.
V. Ya. Bratus’ V. A. Yukhimchuk L. I. Berezhinsky M. Ya. Valakh I. P. Vorona I. Z. Indutnyi T. T. Petrenko P. E. Shepeliavyi I. B. Yanchuk 《Semiconductors》2001,35(7):821-826
The results of a comprehensive study by the methods of IR absorption, Raman scattering, photoluminescence (PL), and electron spin resonance (ESR) of SiOx films prepared by thermal evaporation of SiO in a vacuum are presented. The nature of structural transformations occurring on annealing the films is determined. Annealing in the temperature range 300–600°C gives rise to a PL band at 650 nm, presumably related to structural defects in SiOx film. Raising the annealing temperature further leads to healing of such defects and quenching of the PL band. Silicon precipitates pass from the amorphous to the crystalline state on being annealed at T ann=1100°C, which gives rise to a new PL band at 730 nm. ESR spectra of P b centers were recorded at the interface between randomly oriented silicon nanocrystallites and SiO2. 相似文献
12.
A. Abdolahzadeh Ziabari F.E. Ghodsi 《Materials Science in Semiconductor Processing》2013,16(6):1629-1636
Nanocrystalline cadmium zinc sulfide thin films with different molar ratios were prepared by sol–gel dip-coating in a polyethyleneglycol matrix. After heat treatment in air at 250, 350 and 450 °C, the thin films were characterized by studying their structural, morphological, compositional, optical (linear and nonlinear) and photoluminescence (PL) properties. According to X-ray diffraction (XRD) results, the samples are polycrystalline with a hexagonal crystal structure and an average grain size of 12–18 nm. The surface morphology of the films was examined by scanning electron microscopy (SEM). The results show that the films consist of nanocrystalline grains included in clusters with uniform coverage over the substrate surface. To determine their chemical composition, X-ray photoelectron spectra (XPS) of composite films were measured. The transmittance and bandgap of the films increased with the Zn concentration and decreased with increasing annealing temperature. The refractive index of the films was measured and the related dispersion is discussed in terms of the Wemple–DiDomenico single oscillator model. The third-order nonlinear polarizability of the films was estimated using a semi-empirical relation based on the single oscillator model. The results show that the films are suitable as optical switches. PL spectra were recorded for an excitation wavelength of 210 nm. The emission intensity for the films varied with the Zn ratio and the annealing temperature and the behavior of different peaks is discussed. 相似文献
13.
热氧化磁控溅射金属锌膜制备ZnO纳米棒 总被引:4,自引:0,他引:4
利用射频磁控溅射技术在Si(111)衬底上制备金属锌膜 ,在空气中退火热氧化合成了一维ZnO纳米棒。用X射线衍射 (XRD) ,扫描电子显微镜 (SEM) ,透射电子显微镜 (TEM)和光致发光谱 (PL)对样品进行了结构、形貌及光学特性分析。结果表明 :ZnO纳米棒为六方纤锌矿结构单晶相 ,直径在 30~ 6 0nm左右 ,其长度可达5~ 8μm左右。在 2 80nm波长光激发下 ,有很强的 372nm带边紫外光发射和较微弱的 5 16nm深能级绿光发射 ,说明合成的单晶ZnO纳米棒的质量较高 相似文献
14.
J. M. Zavada R. G. Wilson U. Hömmerich M. Thaik J. T. Seo C. J. Ellis J. Y. Lin H. X. Jiang 《Journal of Electronic Materials》2003,32(5):382-387
We have conducted a study of the material and infrared-luminescence properties of Er-implanted GaN thin films as a function
of annealing. The GaN films, grown by metal-organic chemical-vapor deposition, were coimplanted with Er and O ions. After
implantation, the films were furnace annealed at temperatures up to 1,100°C. Following each annealing stage, the samples were
examined by photoluminescence (PL) measurements and secondary ion-mass spectrometry (SIMS) analysis. In the as-implanted samples,
no PL signal near 1,540 nm could be detected with either above-bandgap or below-bandgap excitation. Only after annealing at
temperatures above 900°C was the 1,540-nm luminescence detectable. Annealing at higher temperatures resulted first in an increase
and then a decrease in the PL-signal intensities. The SIMS data showed that large concentrations of Al, O, and C atoms entered
into the GaN films with high-temperature annealing. The stoichiometric changes in the GaN appear responsible for the changes
in the Er-related luminescence. 相似文献
15.
The Effect of Substrate Material and Postannealing on the Photoluminescence and Piezo Properties of DC-Sputtered ZnO 总被引:1,自引:0,他引:1
Leo P. Schuler Nagarajan Valanoor Paul Miller Ian Guy Roger J. Reeves Maan M. Alkaisi 《Journal of Electronic Materials》2007,36(4):507-518
Abstact Zinc oxide (ZnO) thin films were deposited on various substrates by DC sputtering deposition. Thermal annealing was performed
at up to 1,200°C in N2 for 30 min. The effect was investigated using x-ray diffraction (XRD), photoluminescence (PL) spectra, scanning electron
microscopy (SEM), and piezoresponse force microscopy (PFM). The influence on PL response depends both on substrate material
and annealing temperature. The PFM images reveal that the ZnO films have inversion domains. While annealing improves the piezoresponse,
the inversion domains still persist. The cross-sectional analysis of the inversion domains shows domain boundary widths of
approximately 1.5 nm.
(Received ...; accepted ...) 相似文献
16.
I. E. Tyschenko V. A. Volodin M. Voelskow A. G. Cherkov V. P. Popov 《Semiconductors》2013,47(5):606-611
The crystallization of silicon-on-insulator films, implanted with high doses of hydrogen ions, upon annealing with millisecond pulses is studied. Immediately after hydrogen-ion implantation, the formation of a three-phase structure composed of silicon nanocrystals, amorphous silicon, and hydrogen bubbles is detected. It is shown that the nanocrystalline structure of the films is retained upon pulsed annealing at temperatures of up to ~1000°C. As the temperature of the millisecond annealing is increased, the nanocrystal dimensions increase from 2 to 5 nm and the fraction of the nanocrystalline phase increases to ~70%. From an analysis of the activation energy of crystal phase growth, it is inferred that the process of the crystallization of silicon films with a high (~50 at %) hydrogen content is limited by atomic-hydrogen diffusion. 相似文献
17.
G. A. Kachurin L. Rebohle I. E. Tyschenko V. A. Volodin M. Voelskow W. Skorupa H. Froeb 《Semiconductors》2000,34(1):21-26
Photoluminescence (PL), Raman scattering, and the Rutherford backscattering of α-particles were used to study the formation of the centers of radiative-recombination emission in the visible region of the spectrum on annealing of the SiO2 layers implanted with Ge ions. It was found that the Ge-containing centers were formed in the as-implanted layers, whereas the stages of increase and decrease in the intensities of PL bands were observed following an increase in the annealing temperature to 800°C. The diffusion-related redistribution of Ge atoms was observed only when the annealing temperatures were as high as 1000°C and was accompanied by formation of Ge nanocrystals. However, this did not give rise to intense PL as distinct from the case of Si-enriched SiO2 layers subjected to the same treatment. It is assumed that, prior to the onset of Ge diffusion, the formation of PL centers occurs via completion of direct bonds between the neighboring excess atoms, which gives rise to the dominant violet PL band (similar to the PL of O vacancies in SiO2) and a low-intensity long-wavelength emission from various Ge-containing complexes. The subsequent formation of centers of PL with λm~570 nm as a result of anneals at temperatures below 800°C is explained by agglomeration of bonded Ge atoms with formation of compact nanocrystalline precipitates. The absence of intense PL following the high-temperature anneals is believed to be caused by irregularities in the interfaces between the formed Ge nanoc-rystals and the SiO2 matrix. 相似文献
18.
19.
ZnS films were deposited on porous Si (PS) substrates using a pulsed laser deposition (PLD) technique.White light emission is observed in photoluminescence (PL) spectra, and the white light is the combination of blue and green emission from ZnS and red emission from PS. The white PL spectra are broad, intense in a visible band ranging from 450 to 700 nm. The effects of the excitation wavelength, growth temperature of ZnS films, PS porosity and annealing temperature on the PL spectra of ZnS/PS were also investigated. 相似文献
20.
Hydrogenated silicon nitride(SiNx :H) thin films are deposited on p-type silicon substrates by plasma enhanced chemical vapor deposition(PECVD) using a gas mixture of ammonia and silane at 230 °C.The chemical compositions and optical properties of these films,which are dealt at different annealing temperatures,are investigated by Fourier transform infrared(FTIR) absorption spectroscopy and photoluminescence(PL) spectroscopy,respectively.It is shown that the FTIR presents an asymmetric Si-N stretching mode,whose magnitude is enhanced and position is shifted towards higher frequencies gradually with the increase of the annealing temperature.Meanwhile,it is found that the PL peak shows red shift with its magnitude decreasing,and disappears at 1100 °C.The FTIR and PL spectra characteristics suggest that the light emission is attributed to the quantum confinement effect of the carriers inside silicon quantum dots embedded in SiNx : H thin films. 相似文献