Bright and Efficient Red Light-Emitting Electrochemical Cells with Nondoped Organic Small Molecules: A New Approach

Abstract

We have designed and synthesized two new novel molecules named TBT and PBT for the fabrication of nondoped light-emitting electrochemical cells (LECs). This is for the first time we are reporting red-emitting LECs with nondoped SMs in the history of LECs. Along with excellent thermal stability, the luminogens process better photophysical properties. The fabricated devices produced hyper red color emission with Commission International de I'Eclairage (CIE) coordinates (0.69, 0.30) and (0.73, 0.27) with electroluminescent peaks at 622 and 663 nm for PBT and TBT, respectively. The fabricated devices showed brightnesses of 1955 and 1393 cd/m 2 , current efficiencies 4.59 and 3.09 cd/A, and power efficiencies of 2.77 and 3.81 lm/W for PBT and TBT, respectively.

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

“…Next, neat films of DiKTa-OBuIm and DiKTa-DPA-OBuIm were directly used as active layers. Non-doped small molecule films have shown recently promising results in LEEC devices [ 42 ]. As both emitters are ionic, in principle there is no need to incorporate additional mobile ions.…”

Ionic Multi-Resonant Thermally Activated Delayed Fluorescence Emitters for Light Emitting Electrochemical Cells

“…Non-doped small molecule films have shown recently promising results in LEEC devices. 39 As both emitters are ionic, in principle there is no need to incorporate additional mobile ions.…”

Deep-red light-emitting electrochemical cells based on phosphor-sensitized thermally activated delayed fluorescence

“…In these reported studies, deep-red LECs based on phosphor-sensitized fluorescence 29,30 outperform other types of deep-red LECs, i.e. , employing small molecules, 31–35 conjugated polymers, 36–40 and iTMCs. 41–57 Phosphor-sensitized fluorescence has been proven to be useful in increasing device efficiencies of fluorescent OLEDs to the levels similar to those of phosphorescent OLEDs.…”

“…LECs, which have great potential applications in bio-imaging, telecommunication, night-vision displays, and chemical sensing, commonly showed low device efficiencies, hindering their commercialization. In these reported studies, deep-red LECs based on phosphor-sensitized fluorescence 29,30 outperform other types of deep-red LECs, i.e., employing small molecules, [31][32][33][34][35] conjugated polymers, [36][37][38][39][40] and iTMCs. [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] Phosphor-sensitized fluorescence has been proven to be useful in increasing device efficiencies of fluorescent OLEDs to the levels similar to those of phosphorescent OLEDs.…”

“…21–28 However, the reported long-wavelength, i.e. , deep-red and near-infrared (NIR) LECs, which have great potential applications in bio-imaging, telecommunication, night-vision displays, and chemical sensing, commonly showed low device efficiencies, 29–61 hindering their commercialization. In these reported studies, deep-red LECs based on phosphor-sensitized fluorescence 29,30 outperform other types of deep-red LECs, i.e.…”