Determination of photo-active region in organic thin film solar cells with an organic heterojunction

摘要

The photo-active region in the solar cells consisting of Cu-phthalocyanine (CuPc) and perylenederivative (PV) layers was determined by using exciton blocking layers (EBLs) inserted in these layers. The photocurrent density was low when the EBL was placed near the CuPc/PV interface. With the increase of the distance between the EBL and the CuPc/PV interface, the photocurrent increased. However; when the distance reached a certain value, it leveled off owing to the limited diffusion length of excitons. From the analysis of the relationship between the position of EBL and the photocurrent density, the photo-active regions in the CuPc and PV layers were estimated to be 8 and 12 nm thick from the interface, respectively. (c) 2006 Elsevier B.V. All rights reserved.