[1] [1] Krebs F C. Solar Energy Materials and Solar Cells, 2009, 93(4): 394.

[2] [2] Dennler G, Scharber M C, Brabec C J. Advanced Materials, 2009, 21(13): 1323.

[3] [3] Topp K, Borchert H, Johnen F, et al. J. Phys. Chem. A, 2010, 114(11): 3981.

[4] [4] Chen H Y, Hou J, Zhang S, et al. Nature Photonics, 2009, 3(11): 649.

[5] [5] Chen X, Zhao C, Rothberg L, et al. Applied Physics Letters, 2008, 93: 123302.

[6] [6] Gunes S, Neugebauer H, Sariciftci N S. Chem. Rev., 2007, 107(4): 1324.

[7] [7] Park S H, Roy A, Beaupr S, et al. Nature Photonics, 2009, 3(5): 297.

[8] [8] Chen X, Yang J, Haley L Y X C, et al. Organic Electronics, 2010, 11(12): 1942.

[9] [9] Li G, Shrotriya V, Huang J, et al. Nature Materials, 2005, 4(11): 864.

[10] [10] Campoy-Quiles M, Ferenczi T, Agostinelli T, et al. Nature Materials, 2008, 7(2): 158.

[11] [11] Yao Y, Hou J, Xu Z, et al. Advanced Functional Materials, 2008, 18(12): 1783.

[12] [12] Chen X, Yang J, Lu J, et al. Applied Physics Letters, 2009, 95(13): 3305.

[13] [13] Ko C J, Lin Y K, Chen F C, et al. Applied Physics Letters, 2007, 90: 063509.

[14] [14] Gill W G. Journal Applied Physics, 1972, 43: 5033.