Doping of organic semiconductors and photovoltaic applications

In this thesis the change in charge mobility and cell performance as a result of p type doping of two different organic molecules including polymer and small molecules with dopant, 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) was examined. As polymer, poly(3-hexylthiophene-2,5-diyl) (P3HT), which is the most commonly used p type material in organic solar cells, was used; as small molecule, 4,4′,4′′-Tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA) was used. In solar cell, which was obtained as a result of doping the molecule P3HT, in standard conditions %3.42 efficiency was measured. This value for undoped molecule was obtained %3.2. MTDATA molecule was doped and used as HTM in perovskite solar cells, and it was observed, that it had %0.97 efficiency. Undoped molecule efficiency value also was %0.08. The optical changes in these doped molecules were examined with absorption and fluorecence spectra. To prevent the effects of decreasing charge mobility of organic semiconductors, they were doped with dopant material at the optimum doping rate and then charge mobility values were calculated. The photovoltaic performance of doped organic solar cells was measured with I-V curve analysis and IPCE measurements. Keywords: Organic semiconductor, Organic solar cell (OSC), p type doping, mobility, F4TCNQ.