Etching temperature dependence of optical properties of the electrochemically etched n-GaAs

Zeng, A S; Zheng, Maojun; Ma, Li; Shen, Wei

doi:10.1007/s00339-006-3621-1

Cited by 5 publications

(8 citation statements)

References 25 publications

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“…6,7 The most reasonable assumption is that the green light is emitted by GaAs nanocrystallites. Because the GaAs absorption edge is 1.424 eV, the most consistent explanation for the observed spectral effects is the quantum confinement in nanometer-sized GaAs crystallites.…”

Section: K10mentioning

confidence: 99%

“…2-4 Most -GaAs reported to date have shown a certain degree of inhomogeneity with respect to morphology, surface chemistry, and PL. [5][6][7] showed that the porous layers formed in n + GaAs͑100͒ samples were uniform both laterally and vertically. The porous layers in the n-GaAs͑111͒ samples were relatively uniform, although their thickness fluctuated by as much as 20% on different parts of the wafer.…”

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confidence: 99%

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Formation of Porous GaAs by Pulsed Current Electrochemical Anodization: SEM, XRD, Raman, and Photoluminescence Studies

Ali¹,

Hashim²,

Aziz³

et al. 2009

Electrochem. Solid-State Lett.

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Porous GaAs ͑-GaAs͒ has been fabricated using pulsed current electrochemical etching. Scanning electron microscopy ͑SEM͒ shows that the time off ͑T off ͒, time on ͑T on ͒, and cycle time ͑T͒ can promote thicker and more uniform -GaAs layers compared to those of direct current etching. Choosing suitable pulse parameters produces -GaAs layers with a thickness of 90 m and crystallite size of 2.4 nm. X-ray diffraction ͑XRD͒ shows a high degree of crystallinity of the samples. Photoluminescence ͑PL͒ spectra showed two or three PL bands besides the PL band of the single-crystalline GaAs ͑c-GaAs͒. Peak PL wavelengths were located approximately at 362, 426, and 540 nm.After the discovery of the room temperature visible photoluminescence ͑PL͒ in porous Si, 1 pore formation in III-V materials received a great deal of attention from the scientific community. Several approaches have been used to fabricate porous GaAs ͑-GaAs͒, including electrochemical anodization, spark processed porous, and laser-induced etching. 2-4 Most -GaAs reported to date have shown a certain degree of inhomogeneity with respect to morphology, surface chemistry, and PL. [5][6][7] showed that the porous layers formed in n + GaAs͑100͒ samples were uniform both laterally and vertically. The porous layers in the n-GaAs͑111͒ samples were relatively uniform, although their thickness fluctuated by as much as 20% on different parts of the wafer. Porous layers formed in n − GaAs͑100͒ were characterized by rectangular surface regions of 200 ϫ 300 m, where pores were initiated, while other parts of the surface remained unetched. Maosheng Hao et al. 8 have formed -GaAs using a two-step electrochemical anodization process, producing a high density of pores with uniform distribution in n-type GaAs. More recently, Mavi et al. 4 have fabricated GaAs nanostructure by laser-induced etching using Nd:yttrium aluminum garnet ͑ = 1.06 m͒ laser, producing nanostructure sizes controllable by changing laser parameters.Difficulty in controlling the nanoscale structure and related properties of GaAs remains as the main challenge. This obviously requires correlating the parameters of the synthesis process with the resulting nanostructure. The pulse current electrochemical approach, 9 if it attains sufficiently high controllability at the nanometer scale, seems to be a highly useful technique. In this technique, instead of using a dc current, a sequence of current pulses is used to form a porous material. Porous silicon with controlled thickness has been successfully prepared using this technique, which gives thicker and more uniform porous layers showing higher PL intensity. [10][11][12] The technique was also used to precisely control etching for processing nanodevices because the pulsed mode enables an extremely small etching rate of ϳ10 −5 nm per pulse. 13 In this work, we report on the formation of -GaAs by using the pulse current anodization technique. The main feature is the on/off cycle at fixed current density and electrolyte composition. The time when there is current, ...

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Section: K10mentioning

confidence: 99%

mentioning

confidence: 99%

Formation of Porous GaAs by Pulsed Current Electrochemical Anodization: SEM, XRD, Raman, and Photoluminescence Studies

Ali¹,

Hashim²,

Aziz³

et al. 2009

Electrochem. Solid-State Lett.

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“…However, there are only a few reports on porous direct gap semiconductors GaAs [5] and InP [6]. Porous GaAs have been the subject of intense studies primarily due to its interesting size dependent electronic and optical properties [7]. Different techniques have been used to form porous GaAs [8][9][10], with the electrochemical (anodic) etching technique remains one of the most versatile [11,12].…”

Section: Introductionmentioning

confidence: 99%

Highly Enhanced Green Photoluminescence of as-Anodized n-type Porous GaAs

Ali

Hashim

Aziz

et al. 2010

AIP Conference Proceedings

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In-plane control of morphology and tunable photoluminescence in porous silicon produced by metal-assisted electroless chemical etching Abstract. Porous GaAs films have been prepared by electrochemical anodic etching of n-GaAs in HF based electrolyte at different current densities. The porous nature of the samples has been observed by scanning electron microscopy (SEM). The nanostructure nature of the porous layer has been demonstrated by X-ray diffraction analysis (XRD) and confirmed by photoluminescence spectroscopy (PL). An "infrared" PL band at 864 nm and an enhanced visible "green" PL band envelope around 540 nm were observed. The "green" PL band envelope has been attributed to the quantum confinement in the GaAs nanocrystals.

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“…The blueshift of the optical absorption spectrum and size-dependent luminescence are some examples of the interesting properties exhibited by these nanostructures. Like silicon [2], compound semiconductors such as GaAs [3][4][5][6], GaP [7,8] and InP [9][10][11] are currently being investigated in the form of porous layers using several techniques. Among these techniques, anodic etching remains one of the most versatile, due to its simplicity and low processing cost.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Zeng et al [4] prepared GaAs granular films by electrochemical anodic etching of n-type GaAs in an HCl electrolyte at different temperatures. Raman spectra revealed marked redshift and broadening, which could be explained by a phonon confinement model.…”

Section: Introductionmentioning

confidence: 99%

Correlation of Raman and photoluminescence spectra of electrochemically prepared n-type porous GaAs

Ali

Hashim

Aziz

et al. 2008

Semicond. Sci. Technol.

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Porous GaAs was formed by electrochemical etching of n-type GaAs wafers in HF-or HCl-based solution with different current densities. The porous structure formation has been confirmed by scanning electron microscopy and x-ray diffraction. The samples were subjected to Raman and photoluminescence (PL) spectroscopic investigations. Our results show that the spontaneous emission is originated from extremely small structures. As the porosity increases, there is an increase of the luminescent peak, lower energy shifting of the Raman feature, exhibiting broadening and decreased of first-order longitudinal optic mode peak intensity. In addition, the intensity of the transverse optic (TO) mode was highly enhanced and its peak was broadened due to the breakdown of the polarization selection rule in the case of high-porosity samples. Two new peaks around 200 and 233 cm −1 were observed, which were attributed to α-As and TO-Ga-As-a respectively. Both Raman and PL results were explained using quantum confinement models. There is reasonable agreement between the results obtained from PL and Raman spectroscopic investigations of the etched GaAs samples.

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Etching temperature dependence of optical properties of the electrochemically etched n-GaAs

Cited by 5 publications

References 25 publications

Formation of Porous GaAs by Pulsed Current Electrochemical Anodization: SEM, XRD, Raman, and Photoluminescence Studies

Formation of Porous GaAs by Pulsed Current Electrochemical Anodization: SEM, XRD, Raman, and Photoluminescence Studies

Highly Enhanced Green Photoluminescence of as-Anodized n-type Porous GaAs

Correlation of Raman and photoluminescence spectra of electrochemically prepared n-type porous GaAs

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