In-operando dipole orientation for bipolar injection from air-stable electrodes into organic semiconductorsShow others and affiliations
2026 (English)In: Materials Horizons, ISSN 2051-6347, E-ISSN 2051-6355Article in journal (Refereed) Epub ahead of print
Abstract [en]
Efficient charge-carrier injection from air-stable electrodes into organic semiconductors (OSCs) is essential for fabricating solution-processed organic electronic devices under ambient conditions. Today, this is typically achieved by incorporating doped OSC interlayers, introducing self-assembled dipole monolayers, or adding mobile ions to the active material (AM). Here, we demonstrate an alternative approach that eliminates the need for additional injection layers or ionic additives. We achieve this by blending the dipolar compound TMPE-OH into the electroluminescent polymer Super Yellow (SY) and depositing this sole AM between two air-stable electrodes, forming a single-layer, dipole-doped OLED (D-OLED). By tracking its transient voltage-luminance response, performing impedance spectroscopy, and comparing these characteristics with two other single-layer device concepts, i.e. a neat-SY OLED without a dipolar compound and a light-emitting electrochemical cell (LEC) containing mobile ions, we can establish that the auxiliary dipoles in the D-OLED reorient under the applied driving voltage, enabling fast luminance turn-on and thinning the injection barriers at both electrodes. Finally, we demonstrate that the D-OLED achieves current efficacies comparable to those of SY OLEDs incorporating dedicated injection layers or LECs. Our study establishes dipolar doping as a practical strategy for efficient bipolar charge injection from air-stable electrodes in solution-processed organic semiconductor devices.
Place, publisher, year, edition, pages
Royal Society of Chemistry, 2026.
National Category
Condensed Matter Physics Materials Chemistry
Identifiers
URN: urn:nbn:se:umu:diva-251841DOI: 10.1039/d6mh00161kISI: 001722386700001PubMedID: 41879057Scopus ID: 2-s2.0-105033847104OAI: oai:DiVA.org:umu-251841DiVA, id: diva2:2053913
Funder
Swedish Research Council, 2019-02345Swedish Research Council, 2021-04778The Kempe FoundationsBertil & Britt Svenssons Stiftelse för BelysningsteknikKnut and Alice Wallenberg Foundation, KAW 2024.0497Wallenberg Initiative Materials Science for Sustainability (WISE)EU, European Research Council, 101096650EU, Horizon Europe, 101150699Swedish Research Council, 2021-05784Knut and Alice Wallenberg Foundation, 2023.0089The Kempe Foundations, JCSMK 23-1982026-04-182026-04-182026-04-18