TCAD Simulation of Silicon Pillar Array Solar Cells

  • Lee, Hoong Joo (Department of Electronic Engineering, Sangmyung University)
  • Received : 2017.03.14
  • Accepted : 2017.03.24
  • Published : 2017.03.31

Abstract

This paper presents a Technology-CAD (TCAD) simulation of the characteristics of crystalline Si pillar array solar cells. The junction depth and the surface concentration of the solar cells were optimized to obtain the targeted sheet resistance of the emitter region. The diffusion model was determined by calibrating the emitter doping profile of the microscale silicon pillars. The dimension parameters determining the pillar shape, such as width, height, and spacing were varied within a simulation window from ${\sim}2{\mu}m$ to $5{\mu}m$. The simulation showed that increasing pillar width (or diameter) and spacing resulted in the decrease of current density due to surface area loss, light trapping loss, and high reflectance. Although increasing pillar height might improve the chances of light trapping, the recombination loss due to the increase in the carrier's transfer length canceled out the positive effect to the photo-generation component of the current. The silicon pillars were experimentally formed by photoresist patterning and electroless etching. The laboratory results of a fabricated Si pillar solar cell showed the efficiency and the fill factor to be close to the simulation results.

Keywords

References

  1. Yoon, H. P., Yuwen ,Y. A., Shen, H., Podraza, N. J., Mallouk, T. E., Dickey, E. C., Redwing, J. A., Wronski, C. R., and Mayer, T. S., "Parametric Study of Micropillar Array Solar Cells," Proceeding of IEEE 37th Photovoltaic Specialists Conference, pp. 303-306, 2011.
  2. Shin, J. C., Chanda, D., Chern, W., Yu, K. J., Rogers, J. J., and Li, X., "Experimental Study of Design Parameters in Silicon Micropillar Array Solar Cells Produced by Soft Lithography and Metal-Assisted Chemical Etching," IEEE J. of Photovoltaics, Vol. 2, pp. 129-133, 2012. https://doi.org/10.1109/JPHOTOV.2011.2180894
  3. Park, W. I., Zheng, G., Jiang, X., Tian, B., and Lieber, C. M., "Controlled Synthesis of Millimeter-long Silicon Nanowires with Uniform Electronic Properties," Nano Letters, Vol. 8, pp. 3004-3009, 2008. https://doi.org/10.1021/nl802063q
  4. Spurgeon, J. M., Plass, K. E., Kayes, B. M., Brunschwig, B. S., Atwater, H. A, and Lewisb, N. S., "Repeated Epitaxial Growth and Transfer of Arrays of Patterned, Vertically Aligned, Crystalline Si Wires from A Single Si(111) Substrate," Applied Physics Letters, Vol. 93, pp. 0321121-0301123, 2008.
  5. Garnett, E. and Yang, P., "Light Trapping in Silicon Nanowire Solar Cells," Nano Letters, Vol. 10, pp. 1082-1087, 2010. https://doi.org/10.1021/nl100161z
  6. Wong, S. M., Yu, H. Y., Li, Y., Li, J., Sun, X. W., Singh, N., Lo, P. G. Q., and Kwong, D., "Boosting Short-Circuit Current With Rationally Designed Periodic Si Nanopillar Surface Texturing for Solar Cells," IEEE Trans. Electron Devices, Vol. 58, pp. 3224-3229, 2011. https://doi.org/10.1109/TED.2011.2159978
  7. Cheng, Y., Chen, T., Chang, F., Huang, B., Pan, H., Li, C., Yu, P., and Wu, R., "Fabrication and Modeling of Large-scale Silicon Nanowire Solar Cells for Thin-film Photovoltaics," Proceeding of IEEE 38th Photovoltaic Specialists Conference, pp. 3083-3086, 2011.
  8. Kumar, J., Manhas, S. K., Singh, D., and Vaddi, R., "Optimization of Vertical Silicon Nanowire Based Solar Cell Using 3D TCAD Simulation," Proceeding of 13th International Symposium on Integrated Circuits, pp. 528-531, 2011.
  9. Um, H., Jung, J., Seo, H., Park, K., Jee, S., Mioz, S. A., and Lee, J., "Silicon Nanowire Array Solar Cell Prepared by Metal-Induced Electroless Etching with a Novel Processing Technology," Japanese Journal of Applied Physics, Vol. 49, pp. 04DN021-04DN025, 2010.
  10. Jung, J., Guo, Z., Jee, S., Um H., Park, K., Hyun, M. S., Yang, J. M., and Lee, J., "A Waferscale Si Wire Solar Cell Using Radial And Bulk p-n Junctions, Nanotechnology," Vol. 21, pp. 4453031-44530317, 2010.
  11. Wagner, H., Dastgheib-Shirazi, A., Chen, R., Dunham, S. T., Kessler, M., and Altermatt, P. P., "Improving The Predictive Power Of Modeling The Emitter Diffusion By fully including The Phosphosilicate Glass (PSG) Layer," Proceeding of IEEE 37th Photovoltaic Specialists Conference, pp. 2957-2962, 2011.