Rectifying and photovoltaic effects of organic double-layer film diode based on lightly doped poly(3-methylthiophene)/ 5-methyl-10-(3,5-dinitrobenzyl)-5, 10-dihydrophenazine junction

Abstract

The interface of electrochemically prepared poly(3-methylthiophene) (PMeT) and vacuum-evaporated 5-methyl-10-(3,5-dinitrobenzyl)-5, 10-dihydrophenazine (MDNDP) was used for the organic double-layer film diode Au/PMeT/MDNDP/ Al, which exhibited efficient rectifying and photovoltaic effects. A forward current was observed in darkness when the Au electrode was positively biased with respect to the Al electrode (rectification ratio at ±2.0 V was 210). The short-circuit photocurrent ( J sc, 690 nA cm −2) and the open-circuit photovoltage (670 mV) were observed under white light illumination (irradiated light intensity was 0.75 mW cm −2, transmittance of Al was 0.1). The fill factor and the photo-voltaic power conversion efficiency n' of the diode were 0.23 and 0.14%, respectively. Action spectra of J sc for the Al-side and Au-side illuminations, and optical absorption spectra of an undoped film of PMeT and a sublimed film of MDNDP suggested that the interface between MDNDP and PMeT is the active region for the diode.