共查询到20条相似文献,搜索用时 46 毫秒
1.
The correlation of the excitation-wavelength dependent photoluminescence with the fractal microstructures of porous silicon has been investigated. As the excitation wavelength increases from 340 to 650 nm, the photoluminescence of porous silicon redshifts from 500 to 780 nm. The excitation-wavelength dependent photoluminescence suggests the existence of a size distribution for the large number of silicon nanocrystallites in porous silicon. Using scanning electron microscopy and computer simulation, we have investigated the fractal features of the microstructures of porous silicon. Our results have demonstrated that the fractal features in the microstructures of porous silicon indicate the existence of a size distribution for the silicon nanocrystallites in porous silicon. The recorded excitation-wavelength dependent photoluminescence of porous silicon can be interpreted in terms of the bond-order-length-strength correlation theory. 相似文献
2.
3.
T. Torchynska J. Aguilar-HernandezM. Morales Rodriguez C. Mejia-GarciaG. Contreras-Puente F.G. Becerril EspinozaB.M. Bulakh L.V. ScherbinaY. Goldstein A. ManyJ. Jedrzejewski 《Journal of Physics and Chemistry of Solids》2002,63(4):561-568
Photoluminescence spectra and their dependence on temperature as well as Raman scattering spectra and Atomic Force Microscopy investigations have been used to study the peculiarities of the red photoluminescence band in low-dimensional Si structures, such as porous silicon and silicon oxide films. It has been shown that the red photoluminescence band of porous silicon is complex and can be decomposed into two elementary bands. It was discovered that elementary band intensities depend very much on surface morphology of porous silicon. The same positions of the photoluminescence bands are also observed in silicon oxide films for different oxide composition. Comparative investigation of the PL temperature dependences in porous silicon and silicon oxide films indicates that silicon-oxide defect related mechanisms of some elementary photoluminescence bands are involved. 相似文献
4.
We report the optical properties of Nd-incorporated porous silicon. Photoluminescence and photoluminescence excitation measurements have been performed. Room temperature emission spectra from dried or annealed samples have been studied. While steady-state photoluminescence results indicate porous silicon light absorption by the Nd, the photoluminescence excitation shows a deficiency of energy transfer between porous silicon and Nd ions. 相似文献
5.
Photoluminescence spectra of porous silicon filled by luminescent liquid crystals 5CB and H109 were investigated. It was observed that there were photoluminescence bands corresponding to both porous silicon and liquid crystal in experimental spectra. In addition, the band corresponding to porous silicon increases in comparison with photoluminescence of porous silicon without the filler. Experimental results are explained by the radiating and nonradiating energy transfer from liquid crystal to porous silicon. 相似文献
6.
理论上,采用Bruggeman有效介质近似,研究了有机吸附物对多孔硅微腔的折射率及其光致发光谱的影响.实验上,采用计算机控制的电化学腐蚀法制备了多孔硅微腔样品,并利用机械泵油的蒸气分子与该微腔样品进行相互作用.研究发现,多孔硅微腔发射的窄化光致发光谱对泵油蒸气分子的吸附与脱附很敏感,与之伴随的是该窄化光致发光谱发生明显的峰位移动(可达71nm)和强度变化.结合Bruggeman近似和表面态对多孔硅发光的影响,对实验结果进行了定性解释.实验结果与理论模拟结果符合较好.
关键词:
Bruggeman近似
吸附物
多孔硅微腔
光致发光谱 相似文献
7.
报道了金-多孔硅的稳态光致发光,瞬态光致发光和傅里叶变换红外光谱的研究,讨论了金在多孔硅表面吸附产生的表面电子态对多孔硅光致发光特性的影响。 相似文献
8.
Malek Atyaoui Wissem Dimassi Ghrib Monther Radhouane Chtourou Hatem Ezzaouia 《Journal of luminescence》2012,132(2):277-281
In this work, we present results for Cerium (Ce) doping effects on photoluminescence (PL) properties of porous silicon (PS). Cerium was deposited using electrochemical deposition on porous silicon prepared by electrochemical anodization of P-type (100) Si. From the photoluminescence spectroscopy, it was shown that porous silicon treated with cerium can lead to an increase of photoluminescence when they are irradiated by light compared to the porous silicon layer without cerium. In order to understand the contribution of cerium to the enhanced photoluminescence, energy dispersive X-ray (EDX) spectroscopy, Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and atomic force microscopy (AFM) were performed, and it was shown that the improved photoluminescence may be attributed to the change of Si–H bonds into Si–O–Ce bonds and to a newly formed PS layer during electrochemical Ce coating. 相似文献
9.
10.
11.
12.
Malek Atyaoui Wissem Dimassi Marouan Khalifa Radhouane Chtourou Hatem Ezzaouia 《Journal of luminescence》2012,132(10):2572-2576
The influence of surface treatment of porous silicon (PS) in lanthanum (La) containing solution during different times on its photoluminescence and electrical properties has been investigated. For this purpose, chemical composition, structural, vibrational, photoluminescence and electrical characteristics of the porous silicon layer with and without lanthanum were examined using X-ray diffractometry (XRD), energy dispersive X-ray (EDX) spectroscopy, Fourier transmission infrared (FTIR) spectroscopy, photoluminescence (PL) spectroscopy and current–voltage (I–V) measurements. The results indicate that porous silicon layers treated with lanthanum exhibit an enhancement of photoluminescence intensity and show an improvement current intensity compared to untreated porous silicon layer. 相似文献
13.
I. B. Olenych O. I. Aksimentyeva L. S. Monastyrskii M. R. Pavlyk 《Journal of Applied Spectroscopy》2012,79(3):495-498
Changes in the intensity of light transmitted through polyaniline films caused by an external voltage are used to control the photoluminescence spectrum of nanoporous silicon. A study of the optical-luminescence properties of hybrid porous silicon-polyaniline structures under the influence of an applied external potential shows that polyaniline films deposited on a porous silicon surface can serve as an optical filter for the photoluminescence of porous silicon with an electrically controlled transmission band. 相似文献
14.
Lewis acid mediated hydrosilylation on porous silicon surfaces permits facile incorporation of a wide variety of functionalities through stable silicon–carbon bonds. The surfaces demonstrate high chemical stability with respect to hydrofluoric acid and aqueous base. The effects of the covalently bound surface groups on photoluminescence have been investigated and it was noted that alkyl and alkenyl termination induced only small decreases in photoluminescence efficiency. Aromatic substituents conjugated through a vinyl group, however, bring about almost complete quenching of the observed photoluminescence, regardless of substitution with either electron withdrawing (chloride) or donating (methyl) functionalities. The photoluminescence fatigue of dodecyl terminated surfaces in air for 12–16 h periods has been monitored and compared to unfunctionalized porous silicon. In air, the photoluminescence of dodecyl terminated surfaces degrades faster than the unfunctionalized porous silicon but under inert atmosphere (nitrogen), the rate of photoluminescence fatigue is slow in both cases and approximately equivalent. 相似文献
15.
V. V. Filippov V. P. Bondarenko P. P. Pershukevich V. S. Khomenko 《Journal of Applied Spectroscopy》1997,64(4):514-517
We obtained porous silicon films modified at room temperature by an Eu3+-containing polymer complex. The most intense photoluminescence of Eu3+ implanted in the porous silicon was observed at the wavelengths of 611, 618, 691, and 704 nm. In this case, the intensity
of the intrinsic photoluminescence of strongly irradiated specimens of porous silicon decreased, while the intensity of weakly
emitting films multiply increased. An investigation of the photoexcitation spectra made it possible to establish the effect
of Eu3+-containing complexes on the mechanism underlying the excitation of photoluminescence of porous silicon.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 4, pp. 499–501, July–August, 1997. 相似文献
16.
Yunsen Zhang Donglai Liu Xue Bai Huabing Song Wenyu Li Xiaosong Sun 《Journal of luminescence》2010,130(6):1005-1473
This very paper is focusing on the investigation of porous silicon preparation with n-type silicon wafer by means of electrochemical anodization in the dark and, particularly, on its stable ultraviolet photoluminescence emission. A lateral electrical potential was applied, for this purpose, on silicon wafers, driving the electrons away and letting holes appear on the surface of the silicon wafer to enhance the electrochemical etching process. Characterizations have been made with scanning electronic microscope, fluorescence spectrophotometer and Fourier transform infrared spectroscope. An ultraviolet photoluminescence emission of 370 nm is found in the as-prepared n-type porous silicon, which seems to be well associated with the formation of oxygen-related species (twofold coordinated silicon defect) during the anodic oxidation. The result characterized by photo-bleaching performance indicates that the ultraviolet photoluminescence emission is so stable—only 7% reduction within 3600 s. Meanwhile the morphology of as-prepared n-type porous silicon is investigated. 相似文献
17.
E. S. Demidov A. N. Mikhaylov A. I. Belov M. V. Karzanova N. E. Demidova Yu. I. Chigirinskii A. N. Shushunov D. I. Tetelbaum O. N. Gorshkov E. A. Evropeitsev 《Physics of the Solid State》2011,53(12):2415-2420
It has been shown that the presence of silicon nanoparticles in a layer of porous silicon saturated with tungsten-tellurite
glass causes an increase in the photoluminescence quantum efficiency of erbium (1530 nm) by an order of magnitude in the case
of long-wavelength excitation and an enhancement of the ytterbium photoluminescence (980 nm) by almost 50 times and erbium
photoluminescence by 25 times in the case of short-wavelength pumping. This luminescence enhancement is explained by the formation
of additional channels of transfer of external excitation by silicon nanocrystallites in porous silicon to impurity ytterbium
and erbium ions in tungsten-tellurite glass. 相似文献
18.
Time-resolved photoluminescence from porous silicon coated with a diamondlike carbon film is investigated. The intensity of
the photoluminescence from the carbon film is obserd to increase after deposition, and there is an accompanying change in
the intensity and a shortwavelength shift of the photoluminescence band of porous silicon that depends on the porosity of
its original layers. These changes are explained by the formation of carbon nanoclusters on the surface of the silicon filaments.
Zh. Tekh. Fiz. 68, 83–87 (April 1998) 相似文献
19.
20.
I. E. Maronchuk M. N. Naidenkov M. V. Naidenkova A. V. Sarikov T. L. Voloshina 《Technical Physics》1999,44(1):122-123
It is shown that surface treatment of porous silicon in inorganic acids and solutions of metal chlorides leads to an increase
in the intensity of photoluminescence of this material. In the case of chlorides, a short-wavelength shift of the photoluminescence
maximum is also observed. The effect of a brief high-temperature anneal in vacuum on the photoluminescence of porous silicon
is investigated. Such treatment is observed to cause partial degradation.
Zh. Tekh. Fiz. 69, 133–134 (January 1999) 相似文献