SL 12

HIGH OPEN-CIRCUIT VOLTAGE PHOTOVOLTAIC DEVICES BASED ON MODIFIED CARBON NANOTUBE BLENDS - POLYBITHIOPHENE HETEROJUNCTIONS

R.L. Patyk^a, B.S. Lomba^b, A.F. Nogueira^b, C.A. Furtado^c, A.P. Santos^c, R.M. Q. Mello^d, L. Micaroni^d, I.A. Hümmelgen^a

^aDepartamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531 - 990 Curitiba PR, Brazil

^bLaboratório de Nanotecnologia e Energia Solar, Instituto de Química, Unicamp, C.P. 6154, 13084-971 Campinas, São Paulo, Brazil

^cLaboratório de Química de Nanoestruturas, CDTN/CNEN, Belo Horizonte, MG, Brazil

^dDepartamento de Química, Universidade Federal do Paraná, Caixa Postal 19081, 81531-990 Curitiba PR, Brazil

We investigate photovoltaic devices using modified single wall nanotubes, SWNTs. SWNTs modification with thiophene groups at the edges and defects of SWCNT can improve interaction with a polythiophene matrix, resulting in solar cells with improved performance. We characterized single layer devices prepared with a blend of modified SWNTs and poly(3-octylthiophene), and multilayered devices produced stacking on top of fluorine-doped tin-oxide, an electrochemically deposited polybithiophene layer, a layer of modified SWNT blended with poly(3-octylthiophene) and an evaporated top metal contact, Ca/Al or Al. In case of Ca/Al-top-electrodes, devices achieve open-circuit voltages of 1.8 V and average power conversion efficiency of 1.5 % at irradiance of 16 W.m-2, spectrally distributed following AM1.5.