Publication detail

Role of vertical segregation in semitransparent organic photovoltaics

KOVALENKO, A. GUERERRO, A. GARCIA-BELMONTE, G.

Original Title

Type

journal article in Web of Science

Language

English

Original Abstract

In this work, the efficiency of semitransparent organic photovoltaic (OPV) devices for low intensity applications is investigated as a function of the processing conditions. It is observed that a thermal treatment of the organic layer induces fullerene migration toward the active layer/air interface. This physical process gives rise to different vertical segregation profiles of donor and acceptor molecules. Once the back contact is deposited, the amount of fullerene covering the surface will determine the contact selectivity and leakage current of the device. Control of this leakage current may not be essential for devices fabricated for high illumination condition applications. However, devices to be used under low illumination conditions may be highly influenced by the presence of this parasitic dark current which flows in the opposite direction to photogenerated current. At the proximity of the contacts, the vertical segregation profile is inferred from optical and electrical measurements. In particular, external quantum efficiency (EQE) measurements carried out from a relatively opaque back contact provide local information on the materials spatially close to the light source. Alternatively, capacitance−voltage measurements enable calculation of the percentage of fullerene molecules covering the cathode contact. Overall, a versatile method that can be used in regular and inverted configuration is presented that explains the different behavior observed for devices to be used under low illumination conditions.

Keywords

organic photovoltaics, low illumination conditions, contact selectivity, capacitance−voltage, impedance spectroscopy

Authors

KOVALENKO, A. GUERERRO, A. GARCIA-BELMONTE, G.

RIV year

2014

Released

19. 12. 2014

Publisher

ACS

Location

USA

ISBN

1944-8244

Periodical

ACS APPL MATER INTER

Year of study

2015

Number

State

United States of America

Pages from

1234

Pages to

1239

Pages count

URL

http://pubs.acs.org/doi/pdf/10.1021/am5071859

BibTex

@article{BUT113778,
  author="Alexander {Kovalenko}",
  title="Role of vertical segregation in semitransparent organic photovoltaics",
  journal="ACS APPL MATER INTER",
  year="2014",
  volume="2015",
  number="7",
  pages="1234--1239",
  doi="10.1021/am5071859",
  issn="1944-8244",
  url="http://pubs.acs.org/doi/pdf/10.1021/am5071859"
}