Issue 11, 2013

Marked improvement in the stability of small molecule organic photovoltaics by interfacial modification using self-assembled monolayers to prevent indium diffusion into the active layer

Abstract

This work describes a simple process to improve the stability of small molecule organic photovoltaics (OPVs) that use poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole transport layer (HTL), without reducing the power conversion efficiency (PCE). We investigated the effect of self-assembled monolayers (SAMs) on the degradation of electrical properties caused by the diffusion of indium through the matrix commonly used in OPV devices. X-ray photoelectron spectroscopy depth profiles suggested that the acidic PEDOT:PSS etched the indium from the indium tin oxide (ITO) electrode, which resulted in indium diffusion into and chemical interaction with the active layer. Such behavior was responsible for the deterioration of the device. By inserting a self-assembled monolayer (SAM) with carboxylic acid functional groups at the interface between the ITO and PEDOT:PSS layers, such diffusion could be significantly suppressed. The PCE of the pristine OPV diminished to zero at 49 days post-fabrication under ambient conditions. However, the PCE of the SAM-modified device was reduced by only 30% over the same period, and only to 48% after 98 days. Moreover, the SAMs improved the interfacial electrical properties between the ITO and PEDOT:PSS layers, which maintained the PCE of the device. Our findings suggest a simple approach to improve the stability of OPVs that utilize PEDOT:PSS as the HTL.

Graphical abstract: Marked improvement in the stability of small molecule organic photovoltaics by interfacial modification using self-assembled monolayers to prevent indium diffusion into the active layer

Supplementary files

Article information

Article type
Paper
Submitted
24 Nov 2012
Accepted
10 Jan 2013
First published
10 Jan 2013

J. Mater. Chem. A, 2013,1, 3680-3687

Marked improvement in the stability of small molecule organic photovoltaics by interfacial modification using self-assembled monolayers to prevent indium diffusion into the active layer

M. Chen, Y. Chiou, J. Chiu, A. Tedla and Y. Tai, J. Mater. Chem. A, 2013, 1, 3680 DOI: 10.1039/C3TA01229H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements