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SiC thin films by alternate sputtering
Surface & Coatings Technology 201 (2007) 5408 – 5411 www.elsevier.com/locate/surfcoat
Preparation and annealing effect on photoluminescent properties of Si/SiC thin films by alternate sputtering Jia-Jun Li, Shi-Li Jia, Xi-Wen Du ⁎, Nai-Qin Zhao School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, PR China Available online 7 August 2006
Abstract Si/SiC composite films, namely, Si nano-particles in SiC matrix material, were prepared by using RF alternate sputtering technique and then annealed at high temperature from 1100 to 1400 °C. The photoluminescence (PL) phenomenon was observed in samples annealed over 1200 °C. The PL spectra show two emission bands at about 352 nm and 468 nm and the PL intensity increasing with temperature rising. The blue PL band at 468 nm is related to a quantum size effect of Si nanocrystallites, while the UV PL peak band at 352 nm may be originated from the presence of the Si–O–C bonds grown at high temperature. © 2006 Elsevier B.V. All rights reserved. PACS: 68.60.-p; 73.21.Ac; 81.07.Bc Keywords: Silicon; Silicon carbide; Sputtering; Photoluminescence; Transmission electron microscopy (TEM)
1. Introduction The silicon-based luminescent materials have attracted great attention in recent years because it can combine the state-of-theart silicon integrated circuits with the optoelectronic applications. However, the indirect nature of the silicon band structure prevents the efficient light emission. The formation of nearzero-dimensional structure is one of the most promising methods to achieve the stable light emission, since such a structure can break the momentum conservation law and enable strong radiative recombination. Therefore, extensive research efforts have been focused on the strong luminescence from silicon nanostructures [1–3]. However, most of the works focused on semiconductor nanocrystallites embedded in an insulated host matrix, e.g. SiO2 [4,5], SiN [6,7], Al2O3 [8,9], MgO [10], etc. The composites with Si nanocrystals dispersed in a wide band gap semiconductor (ZnO [11,12], ZnS or ZnSe [13], TiO2 [14]) are rather new due to their functional matrix and special photoluminescence (PL) properties, especially visible PL at room temperature. Two categories of method, composites and multilayers (ML), were usually adopted to prepare silicon nano-structure. The ⁎ Corresponding author. Tel.: +86 22 81523700; fax: +86 22 27405874. E-mail address: [email protected] (X.-W. Du). 0257-8972/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.surfcoat.2006.07.048
former method disperses silicon clusters in the matrix homogeneously, whereas the latter one deposits silicon and matrix layer by layer. In view of controlling the distribution of Si nanocrystals, the ML structure is superior to the composites structure, since it offers at least a certain control on the grain size in the growth direction [15–17]. In the present work, we tried to prepare Si nanoparticles in SiC matrix, a wide band gap functional semiconductor matrix material, using RF alternate sputtering technique. In order to control the Si grain size elaborately, the multilayer method was used. The multilayer structure was annealed at different temperatures and intensive PL was obtained. 2. Experiment The thin films deposition was performed in a RF magnetron sputtering system by sputtering two targets alternatively, one is high-pure silicon target (6-cm diameter, 99.99% purity) and the other is a composite target composed of high-pure silicon (99.99%) and C (99.99%) plates. Flat-surface p-type Si (1 0 0) wafers and halite were used as substrates. The silicon wafers were precleaned by alcohol and acetone. Before the deposition process, the residual gas pressure in the chamber was about 7.0 × 10− 5 Pa, then high-pure Ar (99.999%) was introduced into the reaction chamber in the process of sputtering deposition; the
J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
Fig. 1. Room temperature PL spectra of as-deposited films and annealed films at different temperatures.
flow rate of Ar was 10.0 sccm. The films of Si and SiC were deposited on the substrates alternately keeping the RF power of the composite target at 100 W and the silicon target 40 W under the deposition pressure fixed at 0.5 Pa. A SiC film of about 3 nm was firstly deposited on the substrates and then a Si film of about 1.5 nm was deposited. The process was repeated for 20 cycles with the total thickness of the structure about 90 nm, and an extra SiC layer was deposited as the cover layer finally. The films on silicon wafers were divided into several parts. One part of the samples is as-deposit film and the other samples were annealed at high temperature from 1100 to 1400 °C in high-pure H2 (99.9%) atmosphere for 30 min. The TEM samples were prepared by dissolving halite substrate in deionized water and then catching films on Mo grids. TEM samples were annealed together with those on silicon substrate. HITACHI F4500 Fluorescence spectrophotometer was used to acquire PL spectra. A FEI Technai G2F 20 Transmission Electron Microscope with field-emission gun was used to investigate the microstructure of thin films. The infrared reflection
Fig. 2. HRTEM image of the as-deposited Si/SiC thin films and its diffraction pattern.
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Fig. 3. HRTEM image of the Si/SiC thin films annealed at 1200 °C.
spectra were collected by a Nicolet 560 Fourier transform infrared (FTIR) spectrometer. 3. Results 3.1. PL spectra of thin films Fig. 1 shows the PL spectra of the as-deposited films and the annealed samples at various annealing temperatures. The peaks at 422 nm and 633 nm are not real luminescence from samples; they arise from the frequency multiplication of 211 nm excitation. The spectra demonstrate that the as-deposited sample has no peak and the PL intensity is very low, while after annealing above 1100 °C, two emission bands can be seen: a strong UV PL peak band at about 352 nm (3.52 eV) and a blue PL peak band at about 468 nm (2.65 eV) under excitation of 211 nm. The blue band luminescence was even visible by nakedeye at room temperature. The PL intensity increases with the annealing temperature; moreover, the shape and peak position of PL is independent on annealing temperature, whereas the intensity is strongly dependent on it.
Fig. 4. HRTEM image of the Si/SiC thin films annealed at 1300 °C.
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J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
fore, the change in the PL spectrum is mainly due to the formation of Si nanocrystals and the change of chemical bonds. The visible blue PL peak band at about 468 nm (2.65 eV) light emission are related to the appearance of Si nanocrystals. During the annealing process, the tiny silicon clusters or the ultrafine silicon layers in the multilayer films aggregated into silicon nanocrystals, thus produced a large increase in the PL emission. It has been reported [21,22] that quantum confinement of carriers in Si nanocrystals enlarges the band gap and gives rise to the room temperature PL. The position of the PL maximum is a function of the nanocrystals size owing to the quantum confinement model of Si [23]: Fig. 5. FTIR spectra of the as-deposited and annealed samples.
corr EPL ¼ E0 þ
3:73 0:881 −0:245 þ d 1:39 d
3.2. Structural evolution
Fig. 5 shows the FTIR spectra of the as-deposited Si/SiC films and that after annealing at different temperatures. There are three bands at about 740 cm− 1, 1055 cm− 1 and 1165 cm− 1 in the spectra of annealed samples. The band at 740 cm− 1 is associated with the Si–C bonds [18], the band at about 1160 cm− 1 can be assigned to Si–O–C bonds [19], and the bands between 1100–1000 cm− 1 can be assigned to Si–O–C bonds or Si–O–Si bonds [20].
Where d is the particle diameter of Si nanocrystalline, E0 is corr the band gap of bulk silicon (E0 = 1.12 eV), EPL is the band gap of Si nanocrystals. In the present work, the size of Si nanocrystals is around 2 nm, thus exciton energy is determined as about 2.7 eV, which is pretty similar with the measured PL energy of about 2.65 eV (468 nm). It can be demonstrated that the visible blue PL agrees well with the EPL caused by the Si quantum confinement effect. Moreover, the size of Si nanocrystals keeps almost constant at different annealing temperatures due to the limitation of SiC layer, thus the PL peak keeps stable at about 468 nm. The UV PL band at about 352 nm after annealing may arise from Si–O–C complex compound. The O element may come from the oxidization at low temperature in the heating process before the protective gas H2 take effect. Our results show that although the annealing was conducted in hydrogen atmosphere the influence of O can not be omitted. Effect of Si–O–C bonds on PL has been investigated in many works [24,25]. It was found that the UV PL band at about 350–370 nm was attributed to the formation of a Si–O–C complex compound structure. In the present work, the difference in the FTIR spectra between the as-sputtered films and that after annealing lies in the appearance of Si–C bonds and Si–O–C bonds, or possible Si–O–Si bonds. The intensity of Si–O–C bonds and that of UV photoluminescence are enhanced synchronously with the annealing temperature, which indicates that the UV PL has an intrinsic relation with Si–O–C bonds, namely, the UV PL band at about 352 nm can be related to the Si–O–C bonds formation.
4. Discussions
5. Conclusions
After annealing at high temperature, remarkable change on PL spectrum are the appearance of the peak in ultraviolet range at about 352 nm (3.52 eV) and the peak at about 468 nm (2.65 eV) in visible light range, and the PL intensity increased with temperature. The HRTEM images show that Si nanocrystals with average size of 2 nm distributes randomly throughout the crystallite SiC matrix. The FTIR absorption spectra give evidences of evolution of chemical bond and show that Si–O–C bonds formed after annealing at different temperatures. There-
Si/SiC multilayer films were grown on Si (1 0 0) by RF alternate sputtering. After annealing above 1200 °C, PL spectrum shows a UV PL peak band at about 352 nm (3.52 eV) and a visible blue PL peak band at about 468 nm (2.65 eV), The PL intensity enhanced obviously with temperature increase. PL, TEM and FTIR results suggest that the blue PL peak band at 468 nm is related to a quantum size effect of Si nanocrystallites, while the UV PL peak band at 352 nm may be originated from the presence of the Si–O–C complex compound structure in
Figs. 2–4 show HRTEM images of the thin films before and after annealing at 1200 °C and 1300 °C in H2 ambient for 30 min. In Fig. 2, atomic configuration of the as-deposited film is random and homogeneous, while Fig. 3 shows that Si nanocrystals are formed in the film annealed at 1200 °C. This indicated that the crystalline areas are caused in the process of annealing. The average size of Si nanocrystals is about 2 nm. Many of Si nanocrystals show their (2 2 0) lattice planes with a distance of 0.236 nm. Si nanocrystals have nearly spherical shape. Some of them are marked by circles in Fig. 3. After annealed at 1300 °C, Si nanocrystals with a size of 1–3 nm are distributed randomly throughout crystallite SiC matrix as shown in Fig. 4. The size of Si nanocrystals remains about 2 nm at different annealing temperatures, which indicates that the multilayer method effectively inhibited the growth of the Si nanocrystals. 3.3. Chemical structure of the films: FTIR
J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
samples grown at high temperature. The PL properties of Si/SiC thin films indicate its high potential for UV and blue optoelectronic applications. Acknowledgement This work was supported by the Natural Science Foundation of China (No. 50402010), Foundation of Tianjin Municipal Science and Technology Commission (No. 043800711), and the 985 project of Tianjin University. References [1] L. Canham, Nature 408 (2000) 411. [2] L. Pavesi, L. Dal Negro, C. Mazzoleni, G. Franzo, F. Priolo, Nature 408 (2000) 440. [3] P.M. Fauchet, Materials Today 8 (2005) 26. [4] H. Seifarth, R. Grotzschel, A. Markwitz, W. Matz, P. Nitzsche, L. Rebohle, Thin Solid Films 330 (1998) 202. [5] H. Rinnert, M. Vergnat, Physica. E, Low-Dimensional Systems and Nanostructures 16 (2003) 382. [6] Z. Pei, H.L. Hwang, Appl. Surf. Sci. 212 (2003) 760. [7] Y. Liu, Y. Zhou, W. Shi, L. Zhao, B. Sun, T. Ye, Mater. Lett. 58 (2004) 2397. [8] P.P. Ong, Y. Zhu, Physica. E, Low-Dimensional Systems and Nanostructures 15 (2002) 118.
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[9] Q. Wan, N.L. Zhang, X.Y. Xie, T.H. Wang, C.L. Lin, Appl. Surf. Sci. 191 (2002) 171. [10] N. Koshizaki, H. Umehara, T. Oyama, Thin Solid Films 325 (1998) 130. [11] U. Pal, G. Casarrubias Segura, O. Zarate Corona, Sol. Energy Mater. Sol. Cells 76 (2003) 305. [12] U. Pal, J. Garcia Serrano, N. Koshizaki, T. Sasaki, Mat. Sci. Eng. B-Solid 113 (2004) 24. [13] J.Q. Hu, Y. Bando, J.H. Zhan, D. Golberg, Appl. Phys. Lett. 85 (2004) 3593. [14] S. Takabayashi, R. Nakamura, Y. Nakato, J. Photochem. Photobiol., A Chem. 166 (2004) 107. [15] C. Ternon, F. Gourbilleau, X. Portier, P. Voivenel, C. Dufour, Thin Solid Films 419 (2002) 5. [16] F. Gourbilleau, X. Portier, C. Ternon, P. Voivenel, R. Madelon, R. Rizk, Appl. Phys. Lett. 78 (2001) 3058. [17] M. Zacharias, J. Bläsing, P. Veit, Appl. Phys. Lett. 74 (1999) 2614. [18] K.B. Sundaram, J. Alizadeh, Thin Solid Films 370 (2000) 151. [19] Ch. Voulgaris, A. Panou, E. Amanatides, D. Mataras, Surf. Coat. Technol. 200 (2005) 351. [20] H. Ye, J.Q. Zhao, Y.H. Zhang, J. Appl. Polym. Sci. 91 (2004) 936. [21] A.G. Cullis, L.T. Canham, P.D.J. Calcott, J. Appl. Phys. 82 (1997) 909. [22] Y. Zhu, H. Wang, P.P. Ong, J. Phys. D: Appl. Phys. 33 (2000) 1965. [23] G. Ledoux, O. Guillois, D. Porterat, C. Reynaud, F. Huisken, B. Kohn, V. Paillard, Phys. Rev. B 62 (2000) 15942. [24] J. Zhao, D.S. Mao, Z.X. Lin, B.Y. Jiang, Y.H. Yu, X.H. Liu, H.Z. Wang, G.Q. Yang, Appl. Phys. Lett. 73 (1998) 1838. [25] H. He, Y. Wang, H. Tang, J. Phys.: Condens. Mat. 14 (2002) 11867.
Preparation and annealing effect on photoluminescent properties of Si/SiC thin films by alternate sputtering Jia-Jun Li, Shi-Li Jia, Xi-Wen Du ⁎, Nai-Qin Zhao School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, PR China Available online 7 August 2006
Abstract Si/SiC composite films, namely, Si nano-particles in SiC matrix material, were prepared by using RF alternate sputtering technique and then annealed at high temperature from 1100 to 1400 °C. The photoluminescence (PL) phenomenon was observed in samples annealed over 1200 °C. The PL spectra show two emission bands at about 352 nm and 468 nm and the PL intensity increasing with temperature rising. The blue PL band at 468 nm is related to a quantum size effect of Si nanocrystallites, while the UV PL peak band at 352 nm may be originated from the presence of the Si–O–C bonds grown at high temperature. © 2006 Elsevier B.V. All rights reserved. PACS: 68.60.-p; 73.21.Ac; 81.07.Bc Keywords: Silicon; Silicon carbide; Sputtering; Photoluminescence; Transmission electron microscopy (TEM)
1. Introduction The silicon-based luminescent materials have attracted great attention in recent years because it can combine the state-of-theart silicon integrated circuits with the optoelectronic applications. However, the indirect nature of the silicon band structure prevents the efficient light emission. The formation of nearzero-dimensional structure is one of the most promising methods to achieve the stable light emission, since such a structure can break the momentum conservation law and enable strong radiative recombination. Therefore, extensive research efforts have been focused on the strong luminescence from silicon nanostructures [1–3]. However, most of the works focused on semiconductor nanocrystallites embedded in an insulated host matrix, e.g. SiO2 [4,5], SiN [6,7], Al2O3 [8,9], MgO [10], etc. The composites with Si nanocrystals dispersed in a wide band gap semiconductor (ZnO [11,12], ZnS or ZnSe [13], TiO2 [14]) are rather new due to their functional matrix and special photoluminescence (PL) properties, especially visible PL at room temperature. Two categories of method, composites and multilayers (ML), were usually adopted to prepare silicon nano-structure. The ⁎ Corresponding author. Tel.: +86 22 81523700; fax: +86 22 27405874. E-mail address: [email protected] (X.-W. Du). 0257-8972/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.surfcoat.2006.07.048
former method disperses silicon clusters in the matrix homogeneously, whereas the latter one deposits silicon and matrix layer by layer. In view of controlling the distribution of Si nanocrystals, the ML structure is superior to the composites structure, since it offers at least a certain control on the grain size in the growth direction [15–17]. In the present work, we tried to prepare Si nanoparticles in SiC matrix, a wide band gap functional semiconductor matrix material, using RF alternate sputtering technique. In order to control the Si grain size elaborately, the multilayer method was used. The multilayer structure was annealed at different temperatures and intensive PL was obtained. 2. Experiment The thin films deposition was performed in a RF magnetron sputtering system by sputtering two targets alternatively, one is high-pure silicon target (6-cm diameter, 99.99% purity) and the other is a composite target composed of high-pure silicon (99.99%) and C (99.99%) plates. Flat-surface p-type Si (1 0 0) wafers and halite were used as substrates. The silicon wafers were precleaned by alcohol and acetone. Before the deposition process, the residual gas pressure in the chamber was about 7.0 × 10− 5 Pa, then high-pure Ar (99.999%) was introduced into the reaction chamber in the process of sputtering deposition; the
J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
Fig. 1. Room temperature PL spectra of as-deposited films and annealed films at different temperatures.
flow rate of Ar was 10.0 sccm. The films of Si and SiC were deposited on the substrates alternately keeping the RF power of the composite target at 100 W and the silicon target 40 W under the deposition pressure fixed at 0.5 Pa. A SiC film of about 3 nm was firstly deposited on the substrates and then a Si film of about 1.5 nm was deposited. The process was repeated for 20 cycles with the total thickness of the structure about 90 nm, and an extra SiC layer was deposited as the cover layer finally. The films on silicon wafers were divided into several parts. One part of the samples is as-deposit film and the other samples were annealed at high temperature from 1100 to 1400 °C in high-pure H2 (99.9%) atmosphere for 30 min. The TEM samples were prepared by dissolving halite substrate in deionized water and then catching films on Mo grids. TEM samples were annealed together with those on silicon substrate. HITACHI F4500 Fluorescence spectrophotometer was used to acquire PL spectra. A FEI Technai G2F 20 Transmission Electron Microscope with field-emission gun was used to investigate the microstructure of thin films. The infrared reflection
Fig. 2. HRTEM image of the as-deposited Si/SiC thin films and its diffraction pattern.
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Fig. 3. HRTEM image of the Si/SiC thin films annealed at 1200 °C.
spectra were collected by a Nicolet 560 Fourier transform infrared (FTIR) spectrometer. 3. Results 3.1. PL spectra of thin films Fig. 1 shows the PL spectra of the as-deposited films and the annealed samples at various annealing temperatures. The peaks at 422 nm and 633 nm are not real luminescence from samples; they arise from the frequency multiplication of 211 nm excitation. The spectra demonstrate that the as-deposited sample has no peak and the PL intensity is very low, while after annealing above 1100 °C, two emission bands can be seen: a strong UV PL peak band at about 352 nm (3.52 eV) and a blue PL peak band at about 468 nm (2.65 eV) under excitation of 211 nm. The blue band luminescence was even visible by nakedeye at room temperature. The PL intensity increases with the annealing temperature; moreover, the shape and peak position of PL is independent on annealing temperature, whereas the intensity is strongly dependent on it.
Fig. 4. HRTEM image of the Si/SiC thin films annealed at 1300 °C.
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J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
fore, the change in the PL spectrum is mainly due to the formation of Si nanocrystals and the change of chemical bonds. The visible blue PL peak band at about 468 nm (2.65 eV) light emission are related to the appearance of Si nanocrystals. During the annealing process, the tiny silicon clusters or the ultrafine silicon layers in the multilayer films aggregated into silicon nanocrystals, thus produced a large increase in the PL emission. It has been reported [21,22] that quantum confinement of carriers in Si nanocrystals enlarges the band gap and gives rise to the room temperature PL. The position of the PL maximum is a function of the nanocrystals size owing to the quantum confinement model of Si [23]: Fig. 5. FTIR spectra of the as-deposited and annealed samples.
corr EPL ¼ E0 þ
3:73 0:881 −0:245 þ d 1:39 d
3.2. Structural evolution
Fig. 5 shows the FTIR spectra of the as-deposited Si/SiC films and that after annealing at different temperatures. There are three bands at about 740 cm− 1, 1055 cm− 1 and 1165 cm− 1 in the spectra of annealed samples. The band at 740 cm− 1 is associated with the Si–C bonds [18], the band at about 1160 cm− 1 can be assigned to Si–O–C bonds [19], and the bands between 1100–1000 cm− 1 can be assigned to Si–O–C bonds or Si–O–Si bonds [20].
Where d is the particle diameter of Si nanocrystalline, E0 is corr the band gap of bulk silicon (E0 = 1.12 eV), EPL is the band gap of Si nanocrystals. In the present work, the size of Si nanocrystals is around 2 nm, thus exciton energy is determined as about 2.7 eV, which is pretty similar with the measured PL energy of about 2.65 eV (468 nm). It can be demonstrated that the visible blue PL agrees well with the EPL caused by the Si quantum confinement effect. Moreover, the size of Si nanocrystals keeps almost constant at different annealing temperatures due to the limitation of SiC layer, thus the PL peak keeps stable at about 468 nm. The UV PL band at about 352 nm after annealing may arise from Si–O–C complex compound. The O element may come from the oxidization at low temperature in the heating process before the protective gas H2 take effect. Our results show that although the annealing was conducted in hydrogen atmosphere the influence of O can not be omitted. Effect of Si–O–C bonds on PL has been investigated in many works [24,25]. It was found that the UV PL band at about 350–370 nm was attributed to the formation of a Si–O–C complex compound structure. In the present work, the difference in the FTIR spectra between the as-sputtered films and that after annealing lies in the appearance of Si–C bonds and Si–O–C bonds, or possible Si–O–Si bonds. The intensity of Si–O–C bonds and that of UV photoluminescence are enhanced synchronously with the annealing temperature, which indicates that the UV PL has an intrinsic relation with Si–O–C bonds, namely, the UV PL band at about 352 nm can be related to the Si–O–C bonds formation.
4. Discussions
5. Conclusions
After annealing at high temperature, remarkable change on PL spectrum are the appearance of the peak in ultraviolet range at about 352 nm (3.52 eV) and the peak at about 468 nm (2.65 eV) in visible light range, and the PL intensity increased with temperature. The HRTEM images show that Si nanocrystals with average size of 2 nm distributes randomly throughout the crystallite SiC matrix. The FTIR absorption spectra give evidences of evolution of chemical bond and show that Si–O–C bonds formed after annealing at different temperatures. There-
Si/SiC multilayer films were grown on Si (1 0 0) by RF alternate sputtering. After annealing above 1200 °C, PL spectrum shows a UV PL peak band at about 352 nm (3.52 eV) and a visible blue PL peak band at about 468 nm (2.65 eV), The PL intensity enhanced obviously with temperature increase. PL, TEM and FTIR results suggest that the blue PL peak band at 468 nm is related to a quantum size effect of Si nanocrystallites, while the UV PL peak band at 352 nm may be originated from the presence of the Si–O–C complex compound structure in
Figs. 2–4 show HRTEM images of the thin films before and after annealing at 1200 °C and 1300 °C in H2 ambient for 30 min. In Fig. 2, atomic configuration of the as-deposited film is random and homogeneous, while Fig. 3 shows that Si nanocrystals are formed in the film annealed at 1200 °C. This indicated that the crystalline areas are caused in the process of annealing. The average size of Si nanocrystals is about 2 nm. Many of Si nanocrystals show their (2 2 0) lattice planes with a distance of 0.236 nm. Si nanocrystals have nearly spherical shape. Some of them are marked by circles in Fig. 3. After annealed at 1300 °C, Si nanocrystals with a size of 1–3 nm are distributed randomly throughout crystallite SiC matrix as shown in Fig. 4. The size of Si nanocrystals remains about 2 nm at different annealing temperatures, which indicates that the multilayer method effectively inhibited the growth of the Si nanocrystals. 3.3. Chemical structure of the films: FTIR
J.-J. Li et al. / Surface & Coatings Technology 201 (2007) 5408–5411
samples grown at high temperature. The PL properties of Si/SiC thin films indicate its high potential for UV and blue optoelectronic applications. Acknowledgement This work was supported by the Natural Science Foundation of China (No. 50402010), Foundation of Tianjin Municipal Science and Technology Commission (No. 043800711), and the 985 project of Tianjin University. References [1] L. Canham, Nature 408 (2000) 411. [2] L. Pavesi, L. Dal Negro, C. Mazzoleni, G. Franzo, F. Priolo, Nature 408 (2000) 440. [3] P.M. Fauchet, Materials Today 8 (2005) 26. [4] H. Seifarth, R. Grotzschel, A. Markwitz, W. Matz, P. Nitzsche, L. Rebohle, Thin Solid Films 330 (1998) 202. [5] H. Rinnert, M. Vergnat, Physica. E, Low-Dimensional Systems and Nanostructures 16 (2003) 382. [6] Z. Pei, H.L. Hwang, Appl. Surf. Sci. 212 (2003) 760. [7] Y. Liu, Y. Zhou, W. Shi, L. Zhao, B. Sun, T. Ye, Mater. Lett. 58 (2004) 2397. [8] P.P. Ong, Y. Zhu, Physica. E, Low-Dimensional Systems and Nanostructures 15 (2002) 118.
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[9] Q. Wan, N.L. Zhang, X.Y. Xie, T.H. Wang, C.L. Lin, Appl. Surf. Sci. 191 (2002) 171. [10] N. Koshizaki, H. Umehara, T. Oyama, Thin Solid Films 325 (1998) 130. [11] U. Pal, G. Casarrubias Segura, O. Zarate Corona, Sol. Energy Mater. Sol. Cells 76 (2003) 305. [12] U. Pal, J. Garcia Serrano, N. Koshizaki, T. Sasaki, Mat. Sci. Eng. B-Solid 113 (2004) 24. [13] J.Q. Hu, Y. Bando, J.H. Zhan, D. Golberg, Appl. Phys. Lett. 85 (2004) 3593. [14] S. Takabayashi, R. Nakamura, Y. Nakato, J. Photochem. Photobiol., A Chem. 166 (2004) 107. [15] C. Ternon, F. Gourbilleau, X. Portier, P. Voivenel, C. Dufour, Thin Solid Films 419 (2002) 5. [16] F. Gourbilleau, X. Portier, C. Ternon, P. Voivenel, R. Madelon, R. Rizk, Appl. Phys. Lett. 78 (2001) 3058. [17] M. Zacharias, J. Bläsing, P. Veit, Appl. Phys. Lett. 74 (1999) 2614. [18] K.B. Sundaram, J. Alizadeh, Thin Solid Films 370 (2000) 151. [19] Ch. Voulgaris, A. Panou, E. Amanatides, D. Mataras, Surf. Coat. Technol. 200 (2005) 351. [20] H. Ye, J.Q. Zhao, Y.H. Zhang, J. Appl. Polym. Sci. 91 (2004) 936. [21] A.G. Cullis, L.T. Canham, P.D.J. Calcott, J. Appl. Phys. 82 (1997) 909. [22] Y. Zhu, H. Wang, P.P. Ong, J. Phys. D: Appl. Phys. 33 (2000) 1965. [23] G. Ledoux, O. Guillois, D. Porterat, C. Reynaud, F. Huisken, B. Kohn, V. Paillard, Phys. Rev. B 62 (2000) 15942. [24] J. Zhao, D.S. Mao, Z.X. Lin, B.Y. Jiang, Y.H. Yu, X.H. Liu, H.Z. Wang, G.Q. Yang, Appl. Phys. Lett. 73 (1998) 1838. [25] H. He, Y. Wang, H. Tang, J. Phys.: Condens. Mat. 14 (2002) 11867.