All-Solution Processed Single-Layer WOLEDs Using [Pt(salicylidenes)] as Guests in a PFO Matrix

Author(s)

Germino, Jose Carlos ; Teixeira Alves Duarte, Luis Gustavo ; Mendes, Rodrigo Araujo ; Faleiros, Marcelo Meira ; de Morais, Andreia ; de Freitas, Jilian Nei ; Pereira, Luiz ; Zambon Atvars, Teresa Dib

• Document type: Journal article
• Source: NANOMATERIALS; v. 12, n. 14, p. 21-pg., 2022-07-01.

Abstract

Herein, we report the synthesis and characterization of two Pt(II) coordination compounds, the new platinum(II)[N,N '-bis(salicylidene)-3,4-diaminobenzophenone)] ([Pt(sal-3,4-ben)]) and the already well-known platinum(II)[N,N '-bis(salicylidene)-o-phenylenediamine] ([Pt(salophen)]), along with their application as guests in a poly [9,9-dioctylfluorenyl-2,7-diyl] (PFO) conjugated polymer in all-solution processed single-layer white organic light-emitting diodes. Completely different performances were achieved: 2.2% and 15.3% of external quantum efficiencies; 2.8 cd A(-1) and 12.1 cd A(-1) of current efficiencies; and 3103 cd m(-2) and 6224 cd m(-2) of luminance for the [Pt(salophen)] and [Pt(sal-3,4-ben)] complexes, respectively. The Commission Internationale de l'Eclairage (CIE 1931) chromaticity color coordinates are (0.33, 0.33) for both 0.1% mol/mol Pt(II):PFO composites at between approximately 3.2 and 8 V. The optoelectronic properties of doped and neat PFO films have been investigated, using steady-state and time-resolved photoluminescence. Theoretical calculations at the level of relativistic density functional theory explained these results, based on the presence of the Pt(II) central ion's phosphorescence emission, considering spin-orbit coupling relationships. The overall results are explained, taking into account the active layer morphological properties, along with the device's electric balance and the emitter's efficiencies, according to deep-trap space-charge models. Considering the very simple structure of the device and the ease of synthesis of such compounds, the developed framework can offer a good trade-off for solution-deposited white organic light-emitting diodes (WOLEDs), with further applications in the field of lighting and signage. (AU)

• FAPESP's process: 13/07375-0 - CeMEAI - Center for Mathematical Sciences Applied to Industry
• Grantee: Francisco Louzada Neto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 13/16245-2 - Photophysical properties of thin films of conjugated polymers
• Grantee: Teresa Dib Zambon Atvars
• Support Opportunities: Regular Research Grants