Enhancing photovoltaic device performance by optimizing donor and acceptor layer thicknesses in thermally interdiffused P3OT - C60 films

PMSE 254

Anamika Gopal, agopal@vt.edu1, R. M. Davis, rmdavis@vt.edu2, and James R. Heflin, rheflin@vt.edu1. (1) Department of Physics, Virginia Tech, Blacksburg, VA 24061, (2) Department of Chemical Engineering, Virginia Tech, 130 Randolph Hall, Blacksburg, VA 24061
Concentration gradients achieved by thermally interdiffusing a bilayer, have been shown to drastically improve performance in poly (3-octylthiophene) (P3OT) – C60 photovoltaic devices. We present a thickness variation study to optimize device performance for a given set of interdiffusion parameters. Bilayers interdiffused at an average of 130°C for 5 minutes and air cooled in an inert atmosphere show optimum device performance for P3OT and C60 layer thicknesses within 40nm to 60nm each. The concentration profiles are determined by Auger spectroscopy combined with argon-ion beam milling. The dependence of the photovoltaic efficiency on the starting thicknesses of the two layers is analyzed utilizing a transfer matrix model that yields the optical intensity profile in the film.
 

Joint PMSE/POLY Poster Session
6:00 PM-8:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster

Division of Polymeric Materials: Science & Engineering

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006