Identification of the Origin of Ultralow Dark Currents in Organic Photodiodes

Bibliographische Detailangaben
Veröffentlicht in:	Advanced materials (Deerfield Beach, Fla.). - 1998. - 35(2023), 8 vom: 25. Feb., Seite e2209598
1. Verfasser:	Ma, Xiao (VerfasserIn)
Weitere Verfasser:	Bin, Haijun, van Gorkom, Bas T, van der Pol, Tom P A, Dyson, Matthew J, Weijtens, Christ H L, Fattori, Marco, Meskers, Stefan C J, van Breemen, Albert J J M, Tordera, Daniel, Janssen, René A J, Gelinck, Gerwin H
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2023
Zugriff auf das übergeordnete Werk:	Advanced materials (Deerfield Beach, Fla.)
Schlagworte:	Journal Article bulk-heterojunction dark current organic photodiodes organic semiconductors

Beschreibung
Zusammenfassung:	© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH. Organic bulk heterojunction photodiodes (OPDs) attract attention for sensing and imaging. Their detectivity is typically limited by a substantial reverse bias dark current density (Jd ). Recently, using thermal admittance or spectral photocurrent measurements, Jd has been attributed to thermal charge generation mediated by mid-gap states. Here, the temperature dependence of Jd in state-of-the-art OPDs is reported with Jd down to 10-9 mA cm-2 at -0.5 V bias. For a variety of donor-acceptor bulk-heterojunction blends it is found that the thermal activation energy of Jd is lower than the effective bandgap of the blends, by ca. 0.3 to 0.5 eV, but higher than expected for mid-gap states. Ultra-sensitive sub-bandgap photocurrent spectroscopy reveals that the minimum photon energy for optical charge generation in OPDs correlates with the dark current thermal activation energy. The dark current in OPDs is attributed to thermal charge generation at the donor-acceptor interface mediated by intra-gap states near the band edges
Beschreibung:	Date Completed 24.02.2023 Date Revised 24.02.2023 published: Print-Electronic Citation Status PubMed-not-MEDLINE
ISSN:	1521-4095
DOI:	10.1002/adma.202209598