Degradation through Directional Self-Doping and Homogeneous Density of Recombination Centers Hindered by 1,8-Diiodooctane Additive in Non-Fullerene Organic Solar Cells

Almora O, Wiegand J, Lopez-Varo P, Matt GJ, Brabec C (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Solar RRL Wiley-VCH

DOI: 10.1002/solr.202100024

Abstract

Non-fullerene-based organic solar cells (OSCs) have recently proven to perform with efficiencies above 18%. This is an important milestone for one of the most promising technologies in the fields of flexible and transparent/semitransparent photovoltaics. However, the stability of OSCs is still a challenging issue to meet the industry requirements. Herein, several devices with IT-4F:PM6 as the active layer with and without 1,8-Diiodooctane (DIO) additive are characterized before and after a 1400 h degradation test under 1 sun white light-emitting diode (LED) illumination intensity. The optoelectronic study via impedance spectroscopy under illumination at quasi-open-circuit correlates the use of DIO as an additive with a retarded degradation behavior and an overall improved device performance. In dark conditions, the Mott-Schottky analysis suggests that samples without DIO develop self-doping during degradation, changing the p-i-n doping profile into a p-n type, most likely related to the evolution of the blend demixing. These mechanisms are further confirmed by drift-diffusion simulations. Space-oriented redistribution of shallow trap levels (self-doping) and homogeneous increase in deep-trap levels (nonradiative recombination) are shown to be hindered by the use of the DIO additive.

Authors with CRIS profile

Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET)

Related research project(s)

Projekt E IGK 2495: Energy conversion systems: From Materials to Devices, Teilprojekt E: Lead-Free Perovskite Semiconductors with Tunable Bandgap for Energy Conversion (Projekt E IGK 2495) Jan. 1, 2020 - June 30, 2024

Involved external institutions

Eidgenössische Technische Hochschule Zürich (ETHZ) / Swiss Federal Institute of Technology in Zurich CH Switzerland (CH) L'Institut Photovoltaïque d'Île-de-France (IPVF) FR France (FR) Universitat Jaume I (UJI) ES Spain (ES)

How to cite

APA:

Almora, O., Wiegand, J., Lopez-Varo, P., Matt, G.J., & Brabec, C. (2021). Degradation through Directional Self-Doping and Homogeneous Density of Recombination Centers Hindered by 1,8-Diiodooctane Additive in Non-Fullerene Organic Solar Cells. Solar RRL. https://dx.doi.org/10.1002/solr.202100024

MLA:

Almora, Osbel, et al. "Degradation through Directional Self-Doping and Homogeneous Density of Recombination Centers Hindered by 1,8-Diiodooctane Additive in Non-Fullerene Organic Solar Cells." Solar RRL (2021).

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