Publication detail

Reversible Formation of Gold Halides in Single-Crystal Hybrid-Perovskite/Au Interface upon Biasing and Effect on Electronic Carrier Injection

POSPÍŠIL, J. GUERRERO, A. ZMEŠKAL, O. WEITER, M. GALLARDO, J. J. NAVAS, J. GARCIA-BELMONTE, G.

Original Title

Reversible Formation of Gold Halides in Single-Crystal Hybrid-Perovskite/Au Interface upon Biasing and Effect on Electronic Carrier Injection

Type

journal article in Web of Science

Language

English

Original Abstract

Solar cells, light emitting diodes, X-rays detectors and other electronic devices based on perovskite materials often incorporate gold electrodes, either in direct or indirect contact with the perovskite compound. Whilst it is widely recognized that the external contacts are an essential part of any electronic device, quite often chemical interactions between active layers and contacts deteriorate the operation and induce degradation, being the identification of the chemical nature of such interfacial structures an open question. This work reveals that chemical reactivity of the gold in contact with the perovskite semiconductor leads to the reversible formation of oxidized gold halide species and explains generation of halide vacancies in the vicinity of the interface. Such a reaction is induced by electrical biasing and produces modifications of the current level by favoring the ability of perovskite/Au interfaces to inject electronic carriers. It is shown that the current injection increment does not depend on the halogen source used, either extrinsic by iodine vapor sublimation of Au electrodes, or intrinsic by bias-driven migration of bromide ions. The current level has mainly an electronic origin, in such a way that the increment/suppression of injected currents is connected to the interface reactivity assisted by the intrinsic halogen ion migration inside the perovskite bulk. In addition, it is confirmed the formation of a dipole-like structures at the reacted electrode lowering the potential barrier for electronic carriers. Our findings confirm the important role of adequate selection of the external contacts and suggest progressing in a deeper understanding of contact reactivity as it dominates the operation characteristics, rather than being governed by bulk transport properties of the charge carriers, either electronic or ionic.

Keywords

Carrier injection; electrode reactivity; gold; hybrid perovskites; single crystal

Authors

POSPÍŠIL, J.; GUERRERO, A.; ZMEŠKAL, O.; WEITER, M.; GALLARDO, J. J.; NAVAS, J.; GARCIA-BELMONTE, G.

Released

12. 6. 2019

Publisher

Wiley-VCH

Location

WEINHEIM, GERMANY

ISBN

1616-301X

Periodical

ADVANCED FUNCTIONAL MATERIALS

Year of study

2019

Number

1

State

Federal Republic of Germany

Pages from

1

Pages to

7

Pages count

7

URL

https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.201900881

BibTex

@article{BUT157310,
  author="Jan {Pospíšil} and Antonio {Guerrero} and Oldřich {Zmeškal} and Martin {Weiter} and Juan {Jesus Gallardo} and Javier {Navas} and Germà {Garcia‐Belmonte}",
  title="Reversible Formation of Gold Halides in Single-Crystal Hybrid-Perovskite/Au Interface upon Biasing and Effect on Electronic Carrier Injection",
  journal="ADVANCED FUNCTIONAL MATERIALS",
  year="2019",
  volume="2019",
  number="1",
  pages="1--7",
  doi="10.1002/adfm.201900881",
  issn="1616-301X",
  url="https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.201900881"
}