Detail publikace

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

Originální název

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

Anglický název

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

Jazyk

en

Originální abstrakt

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.

Anglický abstrakt

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.

BibTex


@article{BUT157310,
  author="Jan {Pospíšil} and Oldřich {Zmeškal} and Martin {Weiter}",
  title="Reversible Formation of Gold Halides in Single-Crystal Hybrid-Perovskite/Au Interface upon Biasing and Effect on Electronic Carrier Injection",
  annote="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.",
  address="Wiley-VCH",
  chapter="157310",
  doi="10.1002/adfm.201900881",
  howpublished="online",
  institution="Wiley-VCH",
  number="1",
  volume="2019",
  year="2019",
  month="june",
  pages="1--7",
  publisher="Wiley-VCH",
  type="journal article in Web of Science"
}