Analysis of interface carrier accumulation and relaxation in pentacene/C-60 double-layer organic solar cell by impedance spectroscopy and electric-field-induced optical second harmonic generation

作者：Chen Xiangyu^*; Taguchi Dai; Shino Tatsunori; Manaka Takaaki; Iwamoto Mitsumasa

来源：Journal of Applied Physics, 2011, 110(7): 074509.

DOI：10.1063/1.3642964

By using the impedance spectroscopy (IS) and optical electric-field-induced second harmonic generation (EFISHG) measurement, interfacial carrier relaxation in pentacene/C-60 double-layer organic solar cell (OSC) has been analyzed. The IS measurements showed that the interfacial carrier relaxation time was diminished 70 times under photo illumination, due to the increase of carrier density caused by the photovoltaic effect. The equivalent circuit analysis using a Maxwell-Wagner effect model well accounted for the IS results. On the other hand, the EFISHG measurements directly probed the interfacial carrier behaviors caused by the photovoltaic effect. The results showed the suppression of the Maxwell-Wagner type carrier relaxation in OSCs by applying a voltage corresponding to the open circuit voltage V-oc. EFISHG measurement coupled with IS measurement provides a clear physics picture of interfacial phenomena related to the photovoltaic effect in OSCs.

• 出版日期2011-10-1