Controlling the Chromaticity of Small‐Molecule Light‐Emitting Electrochemical Cells Based on TIPS‐Pentacene

Abstract

5066 wileyonlinelibrary.com the most intriguing archetypal compounds. For instance, remarkable charge mobilities of up to 4.6 cm 2 V −1 s −1 for its solution-sheared thin fi lms applied in OFETs have been achieved. [ 8 ] Recently, the same authors have demonstrated that the control of the structural arrangement in fi lms boosts the fi eld-effect mobility to remarkable values of 11 cm 2 V −1 s −1 . [ 9 ] In addition, this molecule has recently emerged as a paradigm to study singlet fi ssion process in both solution and thin fi lms, owing to its triplet quantum yield formation exceeding values of 100%. [ 5,6,[10][11][12][13] Finally, the sharp red emission at around 650 nm and the moderate photoluminescence quantum yields (PLQYs) when dispersed in a thin fi lm with the electrontransporting host tris(quinoline-8-olato)-aluminum(III) (Alq 3 ) prompted Kafafi and Anthony groups to fabricate the fi rst OLEDs based on trialkylsilylethynyl-substitute pentacenes. [ 14,15 ] As the most remarkable result, the authors demonstrated that through a proper design of the molecular structure a near quantitative internal quantum effi ciency based on the PLQYs of the active layer is realized. [ 16 ] Encouraged by this excellent result, we decided to probe the performance of the archetypal TIPS-pentacene as an emitter in small molecule light-emitting electrochemical cells (SM-LECs).LECs have emerged as an interesting alternative to OLEDs due to the single-layer device architecture based on air-stable electrodes, the high power effi ciencies at very low operation voltages, and the low-cost manufacturing process on any 3D-shaped substrate. [17][18][19][20][21][22] These assets are possible due to the unique mechanism as the active layer comprises a blend of mobile ions and mostly one electroactive compound. [23][24][25][26][27] Up to date, the most representative materials for LECs have been mixtures of a light-emitting polymer, an ion conducting polymer, and an inorganic salt, as well as mixtures of ionic transition-metal complexes (iTMCs) and ionic liquids. [19][20][21] However, Edman and co-workers have recently demonstrated that the LEC concept can be easily expanded to small molecule (SM) materials. [ 28 ] This result represents a landmark toward future breakthroughs in the fi eld, especially if we take into account the very recent achievements in SM-based OLEDs that are considered as the new momentum heading into the third generation of this technology, [29][30][31][32][33] as well as SMs are considered as the third generation of materials for LECs, which is now in its early infancy. [ 28,34 ] Controlling the Chromaticity of Small-Molecule LightEmitting Electrochemical Cells Based on TIPS-Pentacene

Benefits of using BODIPY–porphyrin dyads for developing deep-red lighting sources

“…In line with the few reports on SM-LECs, [31][32][33][34] Fig. 3 depicts the typical device response features of ionic-based lighting devices.…”

Light-Emitting Electrochemical Cells: A Review on Recent Progress

“…It should, however, be acknowledged that a vast majority of the subsequent research on iTMC-LECs have employed an additional electrolyte (often an ionic liquid) in order to attain a reasonably fast turn-on time [4,5]. The LEC field has up until now been dominated by these two principal classes of compounds, although new groups of functional materials, in the form of non-ionic luminescent small molecules [6][7][8][9][10][11][12][13][14], ionic fluorescent small molecules [15][16][17], quantum dots [18,19], and perovskites [20,21], have emerged more recently. Figure 1c presents the chemical structures of a CP, an iTMC, and a luminescent small molecule, as well as a number of electrolytes that have been utilized in recent high-performance LEC devices.…”

Cunning metal core: efficiency/stability dilemma in metallated porphyrin based light-emitting electrochemical cells

“…In stark contrast, the Zn-por and Sn-por devices feature EQE of 0.017% and 0.0061% with lifetimes of hundreds of hours. Noteworthy, the Pt-por device shows similar EQEs to those of both small-molecules LECs [21][22][23] and porphyrin OLEDs. The efficiency differences between the Sn-por and Zn-por devices are expected from the ϕ in thin films, but that between Zn-por and Pt-por devices might be related to both a better ϕ and film morphology.…”

“…[21][22][23] Despite efforts, the design of stable and efficient red-emitting electroluminescent compounds still remains as one of the contemporary challenges in LECs. Herein, we investigate a new strategy to enhance porphyrins towards efficient LECs.…”