White Light-Emitting Electrochemical Cell

Abstract

We report a light-emitting electrochemical cell (LEC) with air-stable electrodes and a solution-processed single-layer active material that emits warm-white light (CIE coordinates = (0.39, 0.43); color rendering index =83) with significant brightness (B) at a low voltage. The carefully tuned trichromatic device exhibits a short turn-on time (∼5 s to B > 100 cd/m(2)), high efficiency (3.1 cd/A at B = 240 cd/m(2)) and good operational stability (17 h at B > 100 cd/m(2)). We also report a blue LEC with a highly respectable set of device properties in the form of a turn-on time of ∼5 s, an efficiency of 3.6 lm/W and 5.6 cd/A, and an uninterrupted operational lifetime of 25 h. Finally, by analyzing data from trichromatic and monochromatic devices as well as from the constituent fluorescent CPs, we are able to point out a viable path toward further improvements in the performance of the white-emitting LEC.

Saturated and Multi‐Colored Electroluminescence from Quantum Dots Based Light Emitting Electrochemical Cells

“…Since the first LEC device was reported almost 20 years ago, most of the related‐research has been devoted to devices incorporating conjugated polymers (PLECs) and ionic transition‐metals complexes (iTMC‐LECs) . To date, QDs‐LECs are still rare.…”

Light-Emitting Electrochemical Cells: A Review on Recent Progress

“…For many applications, it is desirable with broadband white emission, and Sun and co-workers reported an LEC based on a single-emitter fluorene-oxadiazole copolymer that featured white emission, albeit with a modest efficiency of CE = 0.15 cd/A [98]. Higher white-emission efficiencies exceeding 3 cd/A have subsequently been reported from LECs based on a single CP emitter [100,114] and a CP blend [99].…”

Pain Therapeutics: Current and Future Treatment Paradigms. Edited by Charlotte Allerton

“…reported trichromatic WLECs based on blue, green, and red‐emitting polyspirobifluorene‐based copolymers ( P3B , P3G , and P3R , Figure 2). 48 The ion‐transport material trimethylolpropane ethoxylate (TMPE) and the salt LiCF 3 SO 3 were mixed as the electrolyte in the emissive layer. White EL spectra can be easily tailored by adjusting the mixing ratios of blue, green, and red copolymers.…”