Sains Malaysiana 43(6)(2014): 895–898

Nanocrystalline Silicon (nc-Si:H) and Amorphous Silicon (a-Si:H) Based Thin-Film Multijunction Solar Cell

(Silikon Nanohablur (nc-Si: H) dan Silikon Amorfus (a-Si: H) Berasaskan Sel Nipis Filem

Multisimpangan Suria)

SHAHZAD HUSSAIN*, HARIS MEHMOOD & GHULAM ALI

National University of Sciences and Technology (NUST College of Electrical and Mechanical Engineering CE&ME), Rawalpindi, Pakistan, Haris Mehmood, The University of Faisalabad, Faisalabad, Pakistan

Diserahkan: 25 Mac 2013/Diterima: 23 Februari 2014

ABSTRACT

A novel thin-film multijunction solar cell based on nanocrystalline silicon (nc-Si:H) is presented in this paper. Existing thin-film double junction solar cells are based on amorphous silicon carbide (aSiC:H) and amorphous silicon layers. Such solar cells have limited efficiency due to lower absorption and poor charge transport properties of the a-SiC:H layer. These solar cells have maximum achieved efficiency of about 8.8%. In this work, a-SiC:H has been replaced with nc-Si:H layer and the double junction solar cell has been redesigned. The proposed structure has been simulated with Silvaco TCAD (ATLAS). The simulated results indicated a step increase in the performance of the solar cell with open circuit voltage Voc=2.096 V and efficiency η=10.2%. It was proven that the nc-Si:H is a suitable material for the development of an efficient thin film multijunction solar cell.

Keywords: Multijunction; nanocrystalline silicon; solar cell; TCAD; thin-film

ABSTRAK

Sebuah filem nipis sel suria multisimpangan berdasarkan silikon nanohablur (nc-Si: H) dibincangkan dalam kertas ini. Filem nipis dua-simpangan sel suria yang sedia ada adalah berdasarkan silikon karbida amorfus (aSiC: H) dan lapisan silikon amorfus. Sel suria seperti ini mempunyai kecekapan terhad kerana penyerapan yang lebih rendah dan sifat a-SiC: lapisan H yang mempunyai pengangkutan caj yang lemah. Sel suria ini mempunyai kecekapan maksimum kira-kira 8.8%. Dalam kajian ini satu lapisan SiC: H telah digantikan dengan lapisan nc-Si: H dan simpang sel suria kembar telah direka semula. Struktur yang dicadangkan itu telah disimulasikan dengan Silvaco TCAD (ATLAS). Keputusan simulasi menunjukkan peningkatan ketara dalam kecekapan sel suria dengan voltan litar terbuka VLT = 2.096 V dan kecekapan η = 10.2%. Ia membuktikan bahawa nc-Si: H adalah bahan yang sesuai untuk perkembangan filem multisimpangan nipis sel suria yang cekap.

Kata kunci: Filem nipis; multisimpangan; sel suria; silikon nanohablur; TCAD

RUJUKAN

Delley, B. & Steigmeier, E.F. 1993. Quantum confinement in Si nanocrystals. Phys. Rev. B 47: 1397.

Filonovich, S.A., Águas, H., Bernacka-Wojcik, I., Gaspar, C., Vilarigues, M., Silva, L.B., Fortunato, E. & Martins, R. 2009. Highly conductive p-type nanocrystalline silicon films deposited by RF-PECVD using silane and trimethylboron mixtures at high pressure. Vacuum 83: 1253-1256.

Filonovich, S.A., Alpuim, P., Rebouta, L., Bourée, J-E. & Soro, Y.M. 2008. Hydrogenated amorphous and nanocrystalline silicon solar cells deposited by HWCVD and RF-PECVD on plastic substrates at 150°C. J. of Non-Crystalline Solids 354: 2376-2380.

Lee, C-H., Sazonov, A. & Nathan, A. 2005. High-mobility nanocrystalline silicon thin-film transistors fabricated by plasma-enhanced chemical vapor deposition. Appl. Phys. Lett. 86: 222106.

Li, Z., Zhang, X. & Han, G. 2010. Electrical and optical properties of boron-doped nanocrystalline silicon films deposited by PECVD. Phys. Status Solidi A 207: 144-148.

Suntharalingam, V., Fortmann, C.M., Fonash, S.J. & Rubinelli, F.A. 1994. The p/i interface layer in amorphous silicon solar cells: A numerical modeling study. IEEE First World Conf. on Photovoltaic Energy Conversion Vol. 1, Waikoloa, HI. December, 5-9. pp. 618-621.

Yunaz, I.A., Miyajima, S. & Konagai, M. 2010. Silicon based multijunction solar cells with wide-gap aSi1-×C×:H top cell: Experimental and numerical approaches. 35th IEEE Conf. on Photovoltaics Specialists. Honolulu, Hawaii, USA. June 20-25. pp. 317-322.

*Pengarang untuk surat-menyurat; email: s.hussain@ceme.nust.edu.pk