Laser Induced Nanostructure Formation on a Surface of CdZnTe Crystal

Medvíd, A.; Mychko, A.; Plūdons, Artūrs; Naseka, Yu.

doi:10.4028/www.scientific.net/jnanor.11.107

Cited by 6 publications

(11 citation statements)

References 14 publications

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“…Moreover, our recent investigations have shown that laser radiation can be successfully applied for formation of cone-like nanostructures [7-10] with laser intensity, which do not cause melting of the material. The 1D-graded band gap structure in elementary semiconductors was formed due to quantum confinement effect [8].…”

Section: Introductionmentioning

confidence: 99%

Formation mechanisms of nano and microcones by laser radiation on surfaces of Si, Ge, and SiGe crystals

Medvíd

Onufrijevs

Jarimaviciute-Gudaitiene

et al. 2013

Nanoscale Res Lett

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In this work we study the mechanisms of laser radiation interaction with elementary semiconductors such as Si and Ge and their solid solution SiGe. As a result of this investigation, the mechanisms of nanocones and microcones formation on a surface of semiconductor were proposed. We have shown the possibility to control the size and the shape of cones both by the laser. The main reason for the formation of nanocones is the mechanical compressive stresses due to the atoms’ redistribution caused by the gradient of temperature induced by strongly absorbed laser radiation. According to our investigation, the nanocone formation mechanism in semiconductors is characterized by two stages. The first stage is characterized by formation of a p-n junction for elementary semiconductors or of a Ge/Si heterojunction for SiGe solid solution. The generation and redistribution of intrinsic point defects in elementary semiconductors and Ge atoms concentration on the irradiated surface of SiGe solid solution in temperature gradient field take place at this stage due to the thermogradient effect which is caused by strongly absorbed laser radiation. The second stage is characterized by formation of nanocones due to mechanical plastic deformation of the compressed Ge layer on Si. Moreover, a new 1D-graded band gap structure in elementary semiconductors due to quantum confinement effect was formed. For the formation of microcones Ni/Si structure was used. The mechanism of the formation of microcones is characterized by two stages as well. The first stage is the melting of Ni film after irradiation by laser beam and formation of Ni islands due to surface tension force. The second step is the melting of Ni and subsequent manifestations of Marangoni effect with the growth of microcones.

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Section: Introductionmentioning

confidence: 99%

Formation mechanisms of nano and microcones by laser radiation on surfaces of Si, Ge, and SiGe crystals

Medvíd

Onufrijevs

Jarimaviciute-Gudaitiene

et al. 2013

Nanoscale Res Lett

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“…Our previous investigations have shown possibility to form cone-like nanostructures on a surface of elementary semiconductors – Ge [8], Si [9], and solid solutions SiGe [10] and CdZnTe [11]. According to our investigation, nanocone formation mechanism is characterised by two stages for SiGe and CdZnTe solid solutions [6].…”

Section: Introductionmentioning

confidence: 69%

Two-stage model of nanocone formation on a surface of elementary semiconductors by laser radiation

et al. 2012

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In this work, we study the mechanism of nanocone formation on a surface of elementary semiconductors by Nd:YAG laser radiation. Our previous investigations of SiGe and CdZnTe solid solutions have shown that nanocone formation mechanism is characterized by two stages. The first stage is characterized by formation of heterostructure, for example, Ge/Si heterostructure from SiGe solid solutions, and the second stage is characterized by formation of nanocones by mechanical plastic deformation of the compressed Ge layer on Si due to mismatch of Si and Ge crystalline lattices. The mechanism of nanocone formation for elementary semiconductors is not clear until now. Therefore, the main goal of our investigations is to study the stages of nanocone formation in elementary semiconductors. A new mechanism of p-n junction formation by laser radiation in the elementary semiconductor as a first stage of nanocone formation is proposed. We explain this effect by the following way: p-n junction is formed by generation and redistribution of intrinsic point defects in temperature gradient field – the thermogradient effect, which is caused by strongly absorbed laser radiation. According to the thermogradient effect, interstitial atoms drift towards the irradiated surface, but vacancies drift to the opposite direction – in the bulk of semiconductor. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type, a n-p junction is formed. The mechanism is confirmed by the appearance of diode-like current–voltage characteristics after i-Ge irradiation crystal by laser radiation. The mechanism in Si is confirmed by conductivity type inversion and increased microhardness of Si crystal. The second stage of nanocone formation is laser heating up of top layer enriched by interstitial atoms with its further plastic deformation due to compressive stress caused by interstitials in the top layer and vacancies in the buried layer.

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“…Gauss distribution function has form e particles a where is the fenomenological constant. From of the st ures obtained by the laser beam scan the silicon surface [1][2][3] one can see that interparticle dis-ne T ruct the form ning along tances are comparable with wave length. As we can see from the experimental spectra wave length at the left side of the spectra two times larger than at the right side.…”

Section: Numerical Calculations and Discussionmentioning

confidence: 92%

“…The scanning by the laser beam of the semiconductor surface can lead to fabrication of the systems of the nanohills shaped as a cone, which was reported in [1][2][3]. It is well known, that the mechanical stresses appear when the nano-objects are fabricated at the surface [8][9][10][11].…”

Section: Model and Problem Set Upmentioning

confidence: 99%

“…Nowadays the experiments of luminescence of the nanohills fabricated by laser beam scanning along the silicon surface were reported [1][2][3]. The effect of luminescence by the nanohills in the works [1][2][3] was explained by existing varyband structure of the nano-rods. The spatial quantization is the cause of luminescence effect in the nanohills.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Local Field Effects in the Luminescence of the Cone-Like Nanohills

Lozovski¹,

Medvíd²,

Piatnytsia³

2012

OPJ

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The main purpose of the work is to clarify the physical mechanisms which leads to the specific spectrums of the structures [1-3]. The work is based on the ideas of the effective susceptibility. The effective susceptibility of cone-shaped nanohills located at the semiconductor surface is obtained in the frame of local-field approach. The knowledge of the effective susceptibility allows to calculate the optical absorption profiles. Using the approach similar to Levshin rule the photoluminescence spectra were calculated. Obtained results were compared with experimental luminescence spectra obtained earlier. The significant machanisms, that define the peculiarities of the spectra, is the shape of the nanoclasters and the inhomogeneity of the nanohills array are justificated. The main issue of the work is that the cause of the luminescence spectrums has electodynamical nature without spatial quantisation effects

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Laser Induced Nanostructure Formation on a Surface of CdZnTe Crystal

Cited by 6 publications

References 14 publications

Formation mechanisms of nano and microcones by laser radiation on surfaces of Si, Ge, and SiGe crystals

Formation mechanisms of nano and microcones by laser radiation on surfaces of Si, Ge, and SiGe crystals

Two-stage model of nanocone formation on a surface of elementary semiconductors by laser radiation

Local Field Effects in the Luminescence of the Cone-Like Nanohills

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