Various gratings with 700 nm feature spacings are patterned on the reverse side of organic solar cell active layers to increase the path length and constrain light to the cell through total internal reflection. The absorption enhancement is studied for 15, 40, and 120 nm active layers. We were able to confine 9% of the incident light over the wavelength range of 400–650 nm, with thinner gratings having a greater enhancement potential. The measurement setup utilizing an integrating sphere to fully characterize scattered or diffracted light is also fully described.
© 2013 Optical Society of America
Diffraction and Gratings
Original Manuscript: October 8, 2012
Revised Manuscript: November 28, 2012
Manuscript Accepted: January 5, 2013
Published: February 8, 2013
Byron Cocilovo, Akram Amooali, Alejandra Lopez-Santiago, Jacob Favela, Safatul Islam, Binh Duong, Palash Gangopadhyay, Mahmoud Fallahi, Jeanne E. Pemberton, Jayan Thomas, and Robert A. Norwood, "Effect of modular diffraction gratings on absorption in P3HT:PCBM layers," Appl. Opt. 52, 1025-1034 (2013)