About the transparent electrode of the organic photovoltaic cells

Bernede, JC and Nguyen, DT and Cattin, L and Morsli, M and Kanth, SRB and Patil, S (2011) About the transparent electrode of the organic photovoltaic cells. In: EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS, 56 (3).

PDF eur_phy_jou_app_phy_56_2011.pdf - Published Version Restricted to Registered users only Download (477kB) | Request a copy

Abstract

Electrodes and the nature of their contact with organic materials play a crucial role in the realization of efficient optoelectronic components. Whether the injection (organic light-emitting diodes - OLEDs) or collection (organic photovoltaic cells - OPV cells) of carriers, contacts must be as efficient as possible. To do this, it is customary to refer to electrode surface treatment and/or using a buffer layer all things to optimize the contact. Efficiency of organic photovoltaic cells based on organic electron donor/organic electron acceptor junctions can be strongly improved when the transparent conductive anode is coated with a buffer layer (ABL). We show that an ultra-thin gold (0.5 nm) or a thin molybdenum oxide (3-5 nm) can be used as efficient ABL. However, the effects of these ABL depend on the highest occupied molecular orbital (HOMO) of different electron donors of the OPV cells. The results indicate that, in the case of metal ABL, a good matching between the work function of the anode and the highest occupied molecular orbital of the donor material is the major factor limiting the hole transfer efficiency. Indeed, gold is efficient as ABL only when the HOMO of the organic donor is close to its work function Phi(Au). MoO3 has a wider field of application as ABL than gold. The role of the oxide is not so clearly understood than that of Au, different models proposed to interpret the experimental results are discussed.

Item Type:	Journal Article
Publication:	EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS
Publisher:	CAMBRIDGE UNIV PRESS
Additional Information:	Copyright for this article belongs to the Cambridge University Press
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	22 Jun 2012 10:54
Last Modified:	22 Jun 2012 10:54
URI:	http://eprints.iisc.ac.in/id/eprint/44726

Actions (login required)

View Item