Abstract: Anisotropic silicon nanocrystals (Si Ncs) in amorphous Si1-x-yGexCy thin films were obtained by magnetron sputtering deposition and post-annealing process at high temperature. The microstructure and optical properties of anisotropic Si Ncs were analysed by high-resolution transmission electron microscopy, photoluminescence (PL) and UV-visible absorption. The morphology and optical properties were studied in this article, and the formation mechanism stated. The results showed that Si QDs preferentially grow along the directions with the lower strain energy, such as, 〈002〉, 〈113〉 and 〈220〉, forming polymorphic structures. The polymorphic characteristics affected the energy level configuration as indicated by a blue shift. There were two PL spectrums at 2.57 eV and 2.64 eV. UV-visible absorption measurements revealed an enhanced absorption in the energy range of 2.57 eV, 1.89 eV, 1.2 eV and 0.96 eV, which can be adjusted by changing RS/G. That was expected to improve the amount of light quantum yield of photovoltaic cell.
1 Reinders A, Verlinden P, Sark W V, et al. Amorphous and nanocrystalline silicon solar cells[M]. US: John Wiley & Sons,2017. 2 Smyder J A, Krauss T D. Coming attractions for semiconductor quantum dots[J]. Materials Today,2011,14(9):382. 3 Ji X, Yang D R. Research about structure, preparation technologies and efficiency enhancing of thin film silicon tandem solar cells[J]. Materials Review A: Review Papers,2016,30(2):150(in Chinese). 季鑫,杨德仁.硅基薄膜多结太阳能电池的结构、制备技术及其效率优化的研究[J].材料导报:综述篇,2016,30(2):150. 4 Adele F. Optical analysis of C-Si quantum dots embedded in a silica matrix[D]. Delft: Delft University of Technology,2015. 5 Kirsanov N Y, Latukhina N V, Lizunkova D A, et al. Multilayer photosensitive structures based on porous silicon and rare-earth-element compounds: Study of spectral characteristics[J]. Semiconductors,2017,51(3):353. 6 Pavesi L, Turan R. Silicon nanocrystals [M]. India: WILEY-VCH Verlag GmbH & Co. KGaA. Weinheim,2010. 7 Albert P, Mark Kt, Erik C G, et al. Photovoltaic materials: Pre-sent efficiencies and future challenges[J]. Science,2016,352: aad4424. 8 Buljan M, Pinto S R C, Kashtiban R J, et al. Size and spatial homogeneity of SiGe quantum dots in amorphous silica matrix[J]. Journal of Applied Physics,2009,106(8):1427. 9 Jia L J, Fan G P, Zi W,et al. Ge quantum dot enhanced hydroge-nated amorphous silicon germanium solar cells on flexible stainless steel substrate[J]. Solar Energy,2017,144:635. 10 Dutt A, Matsumoto Y, Santana-Rodriguez G, et al. Surface chemistry and density distribution influence on visible luminescence of silicon quantum dots: An experimental and theoretical approach[J]. Physical Chemistry Chemical Physics,2017,19(2):1526. 11 Chen X, Yang W, Duan L, et al.Spectual characteristics of Si quantum dots embedded in SiNx thin films prepared by magnetron Co-sputtering[J].Spectroscopy and Spectral Analysis,2015,35(7):1770(in Chinese). 陈小波,杨雯,段良飞,等.磁控共溅射法沉积的硅量子点SiNx薄膜的光谱特性[J].光谱学及光谱分析,2015,35(7):1770. 12 Liao W, Zeng X, Wen G, et al, Photoluminescences and structrue performances of Si-rich silicon nitride thin films containing Si quantum dots[J]. Acta Physica Sinica,2013,62(12):126801(in Chinese). 廖武刚,曾祥斌,文国知,等.包含硅量子点的富硅SiNx薄膜结构与发光特性[J].物理学报,2013,62(12):126801. 13 Song D Y, Cho E C, Conibeer G, et al. Structural characterization of annealed Si1-xCx/SiC multilayers targeting formation of Si nanocrystals in a SiC matrix[J]. Journal of Applied Physics,2008,103(8):083544. 14 Berbezier I, Ronda A. SiGe nanostructures[J]. Surface Science Reports,2009,64:47. 15 Heitsch A T, Fanfair D D, Tuan H Y, et al. Solution-liquid-solid (SLS) growth of silicon nanowires[J]. Journal of the American Chemical Society,2008,130:54367. 16 Ma F, Ma S L, Xu K W, et al. Energy anisotropy of bimetal core-shell nanorods and its effects on morphology[J]. Nanotechnology,2007,18(44):445101. 17 Tarus J, Tantarimäki M, Nordlund K. Segregation in SiGe clusters[J]. Nuclear Instruments and Methods in Physics Research Section B,2005,228(1-4):51. 18 Chang G R, Ma F, Xu K W, et al. Multi-band silicon quantum dots embedded in an amorphous matrix of silicon carbide[J]. Nanotech-nology,2010,21:465605. 19 He Q, Li J, Chen J, et al. Progress in researches on the application of microalloying in silicon-based solar cells[J]. Materials Review A: Review Papers,2016,30(1):7(in Chinese). 何秋湘,李京伟,陈建,等.微合金化在晶体硅太阳电池中应用的研究进展[J].材料导报:综述篇,2016,30(1):7. 20 Zhu J G, White C W, Budal J D, et al. Growth of Ge, Si, and SiGe nanocrystals in SiO2 matrices[J]. Journal of Applied Physics,1995,78:4386. 21 Klimov V I. Mechanisms for photogeneration and recombination of multiexcitons in semiconductor nanocrystals: Implications for lasing and solar energy conversion[J]. The Journal of Physical Chemistry B,2006,110(34):16827. 22 Ma F, Xu K W, Fan D. Strain energy anisotropy in germanium and other diamond-cubic polycrystalline films[J]. Thin Solid Films,2006,500(1-2):164. 23 Mohanchand P, Jin Z, Guo Y N, et al. Formation of hierarchical nanoring and nanowire heterostructures[J]. Angewandte Chemie International Edition,2009,48(4):780. 24 Wu R S, Luo X F, Yuan C L, et al. Dielectric matrix imposed stress-strain effect on photoluminescence of Ge nanocrystals[J]. Solid State Communications,2009,149(15-16):598. 25 Lujian Jia, Guopeng Fan, Wei Zi, et al. Ge quantum dot enhanced hydrogenated amorphous silicon germanium solar cells on flexible stainless steel substrate[J]. Solar Energy,2017,144:635.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2018, Vol. 32 
