[19p-W531-1~19] 12.5 Organic solar cells

▲ [19p-W531-14] Charge Carrier Generation at Pentacene-C60 Donor-Acceptor Interfaces

〇Richard Murdey¹, Kazuto Nakao¹, Naoki Sato¹ (1.Kyoto Univ.)

Keywords:organic semiconductor,photoconductivity,charge generation

Charge carrier generation yields at the interface of donor/acceptor organic semiconductor thin films were estimated from current-voltage measurements. A new analysis technique was developed which can be applied even when the power conversion efficiency and output current of the device is vanishingly small. One such case arises where overlapped thin films isolate the donor/acceptor junction some distance from the electrodes. Though inefficient, this configuration is desirable as it allows full experimental access to the junction area independently of the cathode and anode. As an example, two pentacene-fullerene devices were compared where the deposition order of the donor and acceptor films was reversed. Junction currents in both devices were determined to be linear with the incident light intensity, and charge generation in the fullerene-on-pentacene device was found to be over ten times more efficient than in the pentacene-on-fullerene device.