ELECTRICAL CHARACTERISTICS AND EFFICIENCY OF ORGANIC SOLAR CELLS WITH (P3HT: ICBA) ACTIVE LAYER AT AMBIENT AIR

Abstract

A combination of narrow band donor polymer and one of the fullerene derivatives provide a possible solution for the production of efficient organic solar cells. The organic active layer is made from a combination of Poly(3-hexylthiophene-2,5-diyl) with 1’,1’’,4’,4’’- tetrahydro-di[1,4] methanonaphthaleno [5,6] fullerene-C60 (P3HT:ICBA). High holes mobility in conjunction with good solubility and partial air stability make regio-regular P3HT electron donor, a reference material of choice for both fundamental and applied research in organic solar cells. Polymers fullerene ICBA organic solar cells are effective acceptors because of their high electron affinity and ability to transport charge effectively. Spin coating was used to deposit the P3HT:ICBA layer from a solution on a ITO substrate. Aluminum electrodes were vapor deposited under vacuum at different stages with a thermal evaporator and a Keithley set-up was used for Current-Voltage (IV) measurements at ambient. The success of this research is measured by effectively building and tests the cells under ambient air conditions, while the efficiency is better appreciated through using a controlled atmosphere with inert gas. Samples were prepared with different P3HT:ICBA blend ratios. While the maximum efficiency known for the best organic cells is more than 10%, the maximum achieved efficiency in this research is 0.89% for 1:1 (P3HT:ICBA) blend ratio. IV curves were made for the cells with illumination of 100 mW/cm2 at 25 ºC.