Ray optical light trapping in silicon microwires: Exceeding the 2n 2 intensity limit

Optics Express

Volumn 19, Issue 4, 2011, Pages 3316-3331

  Kosten, Emily D ^a   Warren, Emily L ^b   Atwater, Harry A ^a,c  

^a California Institute of Technology   (United States)

^b California Institute of Technology   (United States)

^c CALIFORNIA INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ABSORPTION; LIGHT; REFLECTION;

ACCEPTANCE ANGLE; BACK REFLECTORS; ERGODIC LIMIT; EXPERIMENTAL DATA; FREE SPACE; INTENSITY LIMIT; LAMBERTIAN; LIGHT-TRAPPING; LOW FILLING FRACTION; MICROWIRE; OPTICAL EFFECTS; OPTICAL LIGHT; PER UNIT; RAY OPTICS; RAY OPTICS MODEL; SILICON WIRES; WIRE ARRAYS;

WIRE;

EID: 79951642741     PISSN: None     EISSN: 10944087     Source Type: Journal    
DOI: 10.1364/OE.19.003316     Document Type: Article

References (20)

1. M. Kelzenberg, S. Boettcher, J. Petykiewicz, D. Turner-Evans, M. Putnam, E. Warren, J. Spurgeon, R. Briggs, N. Lewis, and H. Atwater, "Enhanced absorption and carrier collection in si wire arrays for photovoltaic applications", Nat. Mater. 9, 239-244 (2010).
2. E. Garnett and P. Yang, "Light trapping in silicon nanowire solar cells", Nano Lett. 10, 1082-1087 (2010).
3. L. Tsakalakos, J. Balch, J. Fronheiser, M. Shih, S. LaBoeuf, M. Pietrzykowski, P. Codella, B. Korevaar, O. Sulima, J. Rand, A. Davuluru, and U. Ropol, "Strong broadband absorption in silicon nanowire arrays with a large lattice constant for photovoltaic applications", J. Nanophoton. 1, 013552(2007).
4. B. Tian, X. Zheng, T. Kempa, Y. Fang, J. Huang, and C. Lieber, "Coaxial silicon nanowires as solar cells and nanoelectronic power sources", Nature 449, 885-889 (2007). (Pubitemid 47598610)
5. E. Garnett and P. Yang, "Silicon nanowire radial p-n junction solar cells", J. Am. Chem. Soc. 130, 9224-9225 (2008). (Pubitemid 352031121)
6. B. Kayes, H. Atwater, and N. Lewis, "Comparison of the device physics principles of planar and radial p-n junction nanorod solar cells", J. Appl. Phys. 7, 114302-114311 (2005).
7. M. Putnam, S. Boettcher, M. Kelzenberg, D. Turner-Evans, J. Spurgeon, E. Warren, R. Briggs, N. Lewis, and H. Atwater, "Si microwire-array solar cells", Energy Environ. Sci. 3, 1037-1041 (2010).
8. L. Hu and G. Chen, "Analysis of optical absorption in silicon nanowire arrays for photovoltaic applications", Nano Lett. 7, 3249-3252 (2007).
9. C. Kenrick, H. Yoon, Y. Yuwen, G. Barber, H. Shen, T. Mallouk, E. Dickey, T. Mayer, and J. Redwing, "Radial junction silicon wire array solar cells fabricated by gold-catalyzed vapor-liquid-solid growth", Appl. Phys. Lett. 97, 143108(2010).
10. K. Peng and S. Lee, "Silicon nanowires for photovoltaic solar energy conversion", Adv. Mater. 20, 1-18 (2010).
11. O. Gunawan, K. Wang, B. Fallahazad, Y. Zhang, E. Tutuc, and S. Guha, "High performance wire-array silicon solar cells", Prog. Photovolt. Res. Appl. 10, 1002(2010).
12. J. Zhu, Z. Yu, G. Burkhard, C. Hsu, S. Connor, Y. Xu, Q. Wang, M. McGehee, S. Fan, and Y. Cui, "Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays", Nano Lett. 9, 279-282 (2009).
13. C. Lin and M. Povinelli, "Optical absorption enhancement in silicon nanowire arrays with a large lattice constant for photovoltaic applications", Nano Lett. 7, 3249-3252 (2007).
14. E. Yablonovitch, "Statistical ray optics", J. Opt. Soc. Am. 72(7), 899-907 (1982).
15. M. Putnam, D. Turner-Evans, M. Kelzenberg, S. Boettcher, N. Lewis, and H. Atwater, "10 μm minority-carrier diffusion lengths in si wire synthesized by cu-catalyzed vapor-liquid-solid growth", Appl. Phys. Lett. 95, 163116(2009).
16. M. Born and E. Wolf, Principles of Optics, 7th Ed. (Cambridge University Press, 1999).
17. We find our model very slightly exceeds the ergodic limit across all aspect ratios for the smallest filling fraction. This is observed across aspect ratios, with no trend with increasing aspect ratios. The maximum amount by which the ergodic limit is exceeded is approximately 1% and is likely due to small inaccuracies in the model.
18. This should not be confused with the areal filling fraction of the wire array. In solar cells, the power can be calculated by multiplying the short circuit current, the open circuit voltage, and the fill factor, where the fill factor accounts for the fact that the current-voltage curve is not square in the power-producing region.
19. K. Plass, M. Filler, J. Spurgeon, B. Kayes, S. Maldonado, B. Brunschwig, H. Atwater, and N. Lewis, "Flexible polymer-embedded si wire arrays", Adv. Mater. 21, 325-328 (2009).
20. C. Bohren and D. Huffman, Absorption and Scattering of Light by Small Particles (Wiley-VCH, 2004).