Electroluminescent Applications Research Articles

Thermally activated delayed fluorescence dyes featuring an intramolecular-locked azaryl ketone acceptor for electroluminescence application

We have developed two novel thermally activated delayed fluorescence (TADF) emitters, IQLO-PXZ and IQLO-DMAC, featuring an intramolecularly locked indeno[1,2-b]quinolin-11-one (IQLO) acceptor. Our comprehensive investigation, including structural analysis, theoretical calculations, and photophysical studies, aims to assess the viability of IQLO-PXZ and IQLO-DMAC as light emitters in electroluminescent devices. Unlike existing aryl ketone-based emitters, IQLO-PXZ and IQLO-DMAC exhibit red-shifted emission due to their structurally rigid and electron-deficient IQLO moiety. The stronger intramolecular charge transfer effect in IQLO-PXZ results in longer-wavelength emission compared to IQLO-DMAC. Both emitters demonstrate significant TADF properties, facilitating efficient triplet-to-singlet spin conversion. When utilized as the emissive core in electroluminescent devices, IQLO-PXZ and IQLO-DMAC achieved long-wavelength electroluminescence peaking at 612 nm and 578 nm, with commendable external quantum efficiencies of 10.3 % and 11.7 %, respectively. These findings underscore the potential of IQLO as an effective acceptor for constructing high-performance TADF electroluminescent materials.

Efficient deep-blue electroluminescence from Ce-based metal halide

Rare earth ions with d-f transitions (Ce3+, Eu2+) have emerged as promising candidates for electroluminescence applications due to their abundant emission spectra, high light conversion efficiency, and excellent stability. However, directly injecting charge into 4f orbitals remains a significant challenge, resulting in unsatisfied external quantum efficiency and high operating voltage in rare earth light-emitting diodes. Herein, we propose a scheme to solve the difficulty by utilizing the energy transfer process. X-ray photoelectron spectroscopy and transient absorption spectra suggest that the Cs3CeI6 luminescence process is primarily driven by the energy transfer from the I2-based self-trapped exciton to the Ce-based Frenkel exciton. Furthermore, energy transfer efficiency is largely improved by enhancing the spectra overlap between the self-trapped exciton emission and the Ce-based Frenkel exciton excitation. When implemented as an active layer in light-emitting diodes, they show the maximum brightness and external quantum efficiency of 1073 cd m−2 and 7.9%, respectively.

Modified surface ligand management of CsPbI3 perovskite quantum dots enables efficient and stable electroluminescent solar cells

Solution-processed CsPbI3 perovskite quantum dots (PQDs) have attracted enormous attention in both photovoltaic and electroluminescent applications in recent years. However, the surface defects of CsPbI3 PQDs in the ligand exchange procedure still suffer the challenge of imperfect passivation, leading to poor device performance and ambient stability. In this work, we propose a modified surface ligand management to deposit CsPbI3 PQD films using a layer-by-layer (LBL) solid-state exchange strategy, and its applications in photovoltaic and electroluminescent devices are studied. The conjugated phenethylammonium iodide (PEAI) ligand, acting as a short-chain ligand with a phenyl group (PEA+ ion) for encapsulating the CsPbI3 PQDs during the LBL procedure, which can both realize enhanced inter-dot coupling and defects passivation compared with conventional post-treatments. We further demonstrate the balanced transport and injection of electrons and holes within the PEAI-LBL based CsPbI3 PQD films. With this approach, the CsPbI3 PQD solar cells based on PEAI-LBL yielded a champion power conversion efficiency (PCE) of up to 14.18% with a high open voltage of 1.23 V, along with obviously electroluminescent red emission properties in one device. Meanwhile, the unencapsulated devices exhibited excellent stability under a high-humidity environment. This strategy should accelerate advancement in utilizing PQDs for bifunctional optoelectronic applications.

Tuning Ag+ and Mn2+ doping in ZnS:Ag,Mn embedded polymers for flexible white light emitting films

Flexible Light Emitting Diodes are versatile lighting solutions that offer bendable and adaptable illumination possibilities. A soft, flexible white luminescent film (1 mm) shows promise for foldable electroluminescent devices and applications. This film was fabricated using ZnS:Ag and Mn. Under different excitation wavelengths, the phosphors emit blue light due to Ag+ luminescence centers and red light from the d-d transition of Mn2+. The blue emission is greatly suppressed at high Mn2+ doping levels, requiring reduced Ag+ doping in co-doped ZnS:Ag,Mn compared to solo-doped ZnS:Ag samples. By adjusting Ag+ and Mn2+ concentrations, the ZnS:Ag(1%),Mn(0.2%) phosphors show a proper intensity ratio of blue and red emissions, making them a promising candidate for future white light applications.

Study the optical properties of Cs3CeI6: First-principles calculations

The band structure, density of states, and optical properties of a novel material, Cs3CeI6 are calculated for the first time using the density functional theory method in first-principles calculations. It is found that Cs3CeI6 possesses a direct bandgap with an energy value of 3.05 eV. Examination of the density of states indicates that the conduction band minimum is primarily composed of Ce-5d and Ce-4f orbitals, while the valence band maximum is mainly contributed by Ce-4f orbitals. Photoluminescence (P.L.) spectroscopy reveals distinctive bimodal emission peaks at 432 and 468 nm, which serve as characteristic signatures of Ce3+ ions. This bimodal emission arises from spontaneous radiative transitions between excited 5d orbitals and the 2F7/2 and 2F5/2 states within the 4f orbital, as confirmed by crystal field calculations. The difference between these two emission peaks corresponds to variations in energy levels associated with Ce3+ ions due to crystal field disturbances. Moreover, Cs3CeI6 exhibits an exciton binding energy of 225 meV due to strong localization effects in Ce-4f orbitals and binding properties inherent in its zero-dimensional structure, promoting exciton formation. Such a substantial exciton binding energy offers significant advantages for potential electroluminescence applications. Based on these findings, we anticipate promising prospects for the use of Cs3CeI6 in electroluminescent devices.

Spectrally narrow band-edge photoluminescence from AgInS2-based core/shell quantum dots for electroluminescence applications.

This study presents a facile synthesis of cadmium-free ternary and quaternary quantum dots (QDs) and their application to light-emitting diode (LED) devices. AgInS2 ternary QDs, developed as a substitute for cadmium chalcogenide QDs, exhibited spectrally broad photoluminescence due to intrinsic defect levels. Our group has successfully achieved narrow band-edge PL by a coating with gallium sulfide shell. Subsequently, an intrinsic difficulty in the synthesis of multinary compound QDs, which often results in unnecessary byproducts, was surmounted by a new approach involving the nucleation of silver sulfide followed by material conversion to the intended composition (silver indium gallium sulfide). By fine-tuning this reaction and bringing the starting material closer to stoichiometric compositional ratios, atom economy was further improved. These QDs have been tested in LED applications, but the standard device encountered a significant defective emission that would have been eliminated by the gallium sulfide shells. This problem is addressed by introducing gallium oxide as a new electron transport layer.

Reblooming of the cis-Bis(2-phenylpyridine) Platinum(II) Complex: Synthesis Updating, Aggregation-Induced Emission, Electroluminescence, and Cell Imaging.

Studies on the syntheses, photophysical properties, and applications of cis-bis(2-phenylpyridine) platinum(II) complex (Pt(ppy)2) family are of great importance, but very limited progress has been achieved to date. Herein, a one-pot method was established for the syntheses of Pt(ppy)2-type complexes Pt-ppy and Pt-tBu. These two compounds were nonemissive in dilute solutions. However, they produced intense red and deep-red phosphorescence in the aggregation and film states, with lifetimes and quantum yields up to 1.92 μs and 70%, respectively, exhibiting unique aggregation-induced emission (AIE) characteristics. According to the experimental and theoretical studies, molecular configuration transformation (MCT) in the excited state may occur because of the d-d transition from the Pt center, causing nonradiative transitions in the solution. Nevertheless, the MCT would be largely restricted by the intermolecular interactions or rigid matrix, thereby enabling efficient phosphorescence in the aggregation state and in the PMMA films. Consequently, the AIE characteristics of Pt-ppy and Pt-tBu probably result from the restriction of molecular configuration transformation (RMCT). Due to the π-π and/or weak Pt-Pt interactions and the concentration-dependent emission characteristics, they emit deep-red and NIR emissions generated by excimer and/or MMLCT emitting species. Inspired by their AIE features, electroluminescence and cell imaging applications are explored. To the best of our knowledge, this is the first comprehensive study on the synthesis optimization, photophysical properties, AIE characteristics, and applications of the Pt(ppy)2-type complexes, which may rebloom the research studies on this type of Pt(II) complex family and provide valuable insights on the development of phosphorescent AIE metal-organic complexes.

Rational Design of Highly Efficient Orange-Red/Red Thermally Activated Delayed Fluorescence Emitters with Submicrosecond Emission Lifetimes.

The development of orange-red/red thermally activated delayed fluorescence (TADF) materials with both high emission efficiencies and short lifetimes is highly desirable for electroluminescence (EL) applications, but remains a formidable challenge owing to the strict molecular design principles. Herein, two new orange-red/red TADF emitters, namely AC-PCNCF3 and TAC-PCNCF3, composed of pyridine-3,5-dicarbonitrile-derived electron-acceptor (PCNCF3) and acridine electron-donors (AC/TAC) are developed. These emitters in doped films exhibit excellent photophysical properties, including high photoluminescence quantum yields of up to 0.91, tiny singlet-triplet energy gaps of 0.01eV, and ultrashort TADF lifetimes of less than 1 µs. The TADF-organic light-emitting diodes employing the AC-PCNCF3 as emitter achieve orange-red and red EL with high external quantum efficiencies of up to 25.0% and nearly 20% at doping concentrations of 5 and 40 wt%, respectively, both accompanied by well-suppressed efficiency roll-offs. This work provides an efficient molecular design strategy for developing high-performance red TADF materials.

Regulating the Distance Between Donor and Acceptor in Space‐Confined Through‐Space Charge Transfer Emitters for Fast Radiative Decays and High‐Efficiency Organic Light‐Emitting Diodes With Low Efficiency Roll‐Offs

AbstractThrough‐space charge transfer (TSCT) emitters featuring thermally‐activated delayed fluorescence (TADF) are extensively researched but suffer from low radiative decay rates (kr,s) due to insufficient through‐space donor/acceptor interactions. Here, space‐confined TSCT TADF emitters 1–3 with a chemically fixed benzophenone acceptor and a triphenylamine donor on different bridges, that is, 1‐methyl‐9,10‐dihydroanthracene for 1, 4‐methyl‐9H‐xanthene for 2 and 4‐methyl‐9H‐thioxanthene for 3, which exhibit reinforced donor/acceptor interactions with shortened donor–acceptor distances, are reported. It is unveiled that there exists an optimal distance between the fixing sites of donor and acceptor. The emitter 2 with such an optimal distance shows both strong donor/acceptor interactions and high molecular rigidity, whereas the emitter 3 with a too short distance exhibits a twisted molecular structure and increased non‐radiative deactivation. In solution, 1–3 shows high kr,s up to 3.0 × 107 s−1. In doped films, 1–3 exhibits green emission with high kr,s up to 8.3 × 106 s−1 and photoluminescent efficiency up to 0.96. Organic light‐emitting diodes based on 1–3 afford high external quantum efficiencies up to 23.1% and largely alleviated efficiency roll‐offs. The work demonstrates that using rigid bridges that render an optimal donor–acceptor distance is crucial to the development of highly efficient TSCT emitters with fast radiative decays for electroluminescence applications.

Eliminating Nanocrystal Surface Light Loss and Ion Migration to Achieve Bright Mixed-Halide Blue Perovskite LEDs

Blue light-emittin g diodes (LEDs) are important components for perovskite electroluminescence applications, which still suffer from insufficient luminescence efficiency and poor stability. In Cl/Br mixed perovskite NCs, surficial defects cause severe light failure and ion migration, the in-depth mechanism of which is also not clear. To gain insights into these issues, we employ the ligand post-addition approach for mixed Cl/Br NCs by using octylammonium hydrobromide (OctBr) ligands, which effectively decrease surficial light loss and block ion migration pathways. The passivated CsPbCl1.5Br1.5 NCs exhibit exceptional blue emission with 95% PLQY, and the electroluminescence spectra of LEDs are located at the initial positions at the initial states. The treated NC blue devices show a negligible color shift as the voltage increases, which proves that electric-field-driven ion migration is drastically suppressed. In addition, OctBr-treated CsPbCl1.5Br1.5 and CsPbClBr2 NC LEDs show high external quantum efficiencies of 2.42 and 3.05% for emission peaks at 456 and 480 nm, respectively. Our work identified the nature of NC surface defects and provided a surficial modification approach to develop high-performance and color-stable blue mixed-halide perovskite LEDs.

Highly Flexible Electroluminescent Devices Based on Super Durable AlN‐Dispersed Ag Ultrathin Films

AbstractHigh performance and durable electrodes are prerequisites for the stable operation of various optoelectronic devices, such as alternating current electroluminescence (ACEL) applications. As for the flexible electrodes based on ultrathin metals, which have attracted much attention in recent years, stability problems as evidenced by optically lossy and electrical degradation of the silver (Ag) layer in the service environment are the key issues to be solved before its practical application. This work prepares ultrathin and stable doped silver films by introducing a small amount of AlN during the sputtering process. The Ag‐AlN thin films exhibit a comprehensive stability promotion in terms of high temperature (250 °C in the air) and damp‐heat (85 °C, 85% relative humidity (RH) for 12 h) test compared with pure Ag counterpart. In addition, flexible ACEL devices based on AZO/Ag‐AlN/AZO/polyethylene terephthalate (PET) films with a luminance of 176.1 cd m−2 at 300 V and 400 Hz and excellent luminescence performance and mechanical flexibility under operating conditions are developed. Such ACEL devices based on these ultrathin and durable Ag‐AlN films are up‐and‐coming in practical, flexible electronics applications.

Plasma-assisted gas-phase aggregation of clusters for functional nanomaterials

The application of low-temperature plasma-based methods for the synthesis of functional nanomaterials has been growing for several decades and nanoparticles (NPs) play an increasing role in this effort. NPs have been considered for numerous applications such as optoelectronic energy conversion, electrocatalysis for fuel cells, novel plasmonic materials, electroluminescence, macromolecular self-assembly, supramolecular chemistry, and biomedical applications. The focus of this review will be devoted to NPs prepared by vacuum-based plasma-assisted sources. In the majority of cases, plasma has been excited by a planar magnetron. At first, concisely, the state-of-the-art of plasma-based gas aggregation cluster sources is presented. Then, the stability of the deposition process and enhancement of the production yield as well as tailoring of the composition, structure, and shape of NPs are discussed. In addition, in-flight modification of NPs, the interaction of NPs with a substrate, and deposition onto the liquids are presented.

Tuning the Red Emission to Instigate Intrinsic White-Light Emission in Single-Phase Phosphor with Excellent Color Rendering Index.

There is ever-growing interest to develop intrinsic white light emitting single-phase phosphors that have high CRI, devoid of bluish tinge, ease of synthesis and are scalable. Herein, manipulating vacuum pressure to instigate white light emission in Cu2+ -doped-ZnS phosphors is reported. The detailed X-ray diffraction and electron microscopy confirm the cubic phase of Cu2+ -doped-ZnS phosphor having agglomerated particles (∼130-150 nm). The incorporation of Cu2+ in the ZnS lattice is substantiated by the anti-Stokes shift of Raman peaks and shifting of XRD peaks to higher 2θ values. Upon increasing Cu2+ doping concentration, the resulted decrease in the FWHM of XRD peaks implies shrinkage of the ZnS lattice. Interestingly, by tailoring the excitation wavelength, the stoichiometry of dopant ion, and defect states by varying the vacuum pressure, the optimized ZSC-3 (3% Cu2+ -doped-ZnS) displays the origin of clear blue, green and red emission bands, consequently giving rise to white light emission (CIE values: 0.345:0398). The PLQY and average lifetime calculated for ZSC-3 are 5.98% and 1.5 ms, respectively. Such intense white light emission prompted to fabricate a prototype using a 310 nm UV LED. It exhibits high CRI (97) and warm CCT (4538 K), meeting highly desired values for a white light-emitting phosphor for different lighting and electroluminescence applications.

Engineering Coinage Metal Nanoclusters for Electroluminescent Light-Emitting Diodes.

Coinage metal nanoclusters (MNCs) are a new type of ultra-small nanoparticles on the sub-nanometer (typically < three nm) scale intermediate between atoms and plasmonic nanoparticles. At the same time, the ultra-small size and discrete energy levels of MNCs enable them to exhibit molecular-like energy gaps, and the total structure involving the metal core and surface ligand together leads to their unique properties. As a novel environmentally friendly chromophore, MNCs are promising candidates for the construction of electroluminescent light-emitting diodes (LEDs). However, a systematic summary is urgently needed to correlate the properties of MNCs with their influences on electroluminescent LED applications, describe the synthetic strategies of highly luminescent MNCs for LEDs’ construction, and discuss the general influencing factors of MNC-based electroluminescent LEDs. In this review, we first discuss relevant photoemissions of MNCs that may have major influences on the performance of MNC-based electroluminescent LEDs, and then demonstrate the main synthetic strategies of highly luminescent MNCs. To this end, we illustrate the recent development of electroluminescent LEDs based on MNCs and present our perspectives on the opportunities and challenges, which may shed light on the design of MNC-based electroluminescent LEDs in the near future.

Enhancing the stability of environmental resistance of alloyed CdZnSeS@ZnS quantum dots by doping Ti ions into shell layer

Colloidal quantum dots (QDs) are promising luminescent materials for display and lighting, but their stability has long been an issue. Here, we designed a passivation strategy of doping Ti ions into the shell of alloyed CdZnSeS@ZnS QDs. The results showed that Ti ions were successfully doped into the ZnS shell and the stability of QDs was improved. In the aging test, the Ti ions doped QDs maintained 51.4% of the initial performance after 90 h of aging, while the pristine QDs decreased to less than 25% of the initial value. In addition, we discuss the reasons why Ti ions doping improves the stability of QDs. Ti ions are found to form Ti–S bonds in the ZnS shell, which has high binding energy and strong oxidation resistance. Most importantly, since there is no external physical insulating coating, the optimized QDs can also be directly used in electroluminescent devices, showing great potential in electroluminescence applications.

New pyridylimidazole-based near-infrared iridophosphors: Synthesis, photophysical properties, and electroluminescence application

A pair of highly efficient near-infrared (NIR) phosphorescent iridium(III) complexes (NIR-Ir1 and NIR-Ir2) based on pyridylimidazole derivatives are rationally designed. 1-(Benzo [b]thiophen-2-yl)isoquinoline is selected as the cyclomedtalating ligand for complexes, which determines the near-infrared phosphorescence. 2-(1H-imidazole-2-yl)pyridine and 2-(pyridin-2-yl)-1H-benzo[d]imidazole serve as the ancillary ligands, which aims to finely adjust the photophysical properties of these two NIR iridophosphors. At room temperature, both complexes exhibit intense near-infrared phosphorescence and the emission spectra well overlap with each other (685 nm with 750 nm as the emission shoulder for NIR-Ir1 and NIR-Ir2), high photoluminescence quantum yield (0.10 for NIR-Ir1, 0.13 for NIR-Ir2) in dichloromethane. The pyridylimidazole-type ancillary ligands incorporated into the complexes enable the effective NIR phosphorescence and the robust chemical stability for NIR organic light-emitting diodes (OLEDs). The preliminary results show that the maximum luminescence and external quantum efficiency for the OLEDs based on new NIR complexes with electroluminescence peaked at around 690 nm are 1,464 cd/m2 and 1.48%, respectively.

Intramolecular exciplex-typed molecule based on a stereoscopic V-shaped aromatic macrocycle and investigation of host-dependence of exciton utilization

Through-space charge transfer (TSCT) has been increasingly utilized for the design of efficient thermally activated delayed fluorescence (TADF) emitters. TSCT molecular skeletons with spatially and electronically confined D/A subunits can provide a small ΔEST, and also ease for fine control of CT properties within a single molecule. However so far TSCT-TADF molecules have not been fully investigated. Herein, we report a new ortho-position molecular pattern for TSCT-TADF design, using a stereoscopic V-shaped aromatic macrocycle of electron-deficient oxacalix[2]arene[2]triazine to “clip” the electron-rich triphenylamine unit. The new emitter OC2A2T-TPA exhibits a small ΔEST of 18 meV, and the OLED device that uses high-energy-level host DPEPO realizes the first-time electroluminescence application of OC2A2T-type macrocyclic compounds by achieving an impressive external quantum efficiency (EQE) of 14.6 %. Further host-dependence investigation reveals that OC2A2T-TPA actually behaves like an intramolecular exciplex, exhibiting high exciton utilization once its high-lying locally excited (LE) states on D/A could be sensitized first in the case of DPEPO host, otherwise low exciton utilization in the case of lower-energy-level mCP host. This work opens a way to enrich TSCT-TADF design and clarifies the importance to involve the high-lying LE states in the energy transfer routes for high-efficiency intramolecular-exciplex molecules.

Triphenylamino or 9-phenyl carbazolyl-substituted pyrimidine-5-carbonitriles as bipolar emitters and hosts with triplet harvesting abilities

To obtain highly efficient organic semiconductors exhibiting fast emission decays, triplet-harvesting abilities and good bipolar charge-transporting properties for optoelectronic applications, compounds containing triphenylamine or 9-phenylcarbazole as donor moieties and pyrimidine-5-carbonitrile as electron-withdrawing unit were synthesised. Toluene solutions of the compounds demonstrated high photoluminescence quantum yields reaching 98%. As required for electroluminescent device applications, compound containing triphenylamino moiety showed high mobilities of both electrons and holes, which reached 4.4 × 10−4 cm2/V × s and 7.3 × 10−3 cm2/V × s, respectively at electric field of 3.6 × 105 V/cm. This triplet-harvesting mechanism was confirmed by the theoretical and experimental studies including a femtosecond transient absorption pump−probe technique and time-resolved electroluminescence spectroscopy. Pure-blue and greenish-blue fluorescent organic light-emitting diodes (OLEDs) with external quantum efficiency (EQE) reaching 7% and 6%, corresposndingly, were obtained using the newly synthesised compounds as emitters. The operation time (T50) of ca. 650 h were observed for blue OLED and of ca. 3800 h for greenish-blue OLED until reaching the half initial brightness (100 cd/m2). EQE of more than 20% and T50 exceeding 20,000 h were observed for electroluminescent devices based on emitter characterised by triplet−triplet annihilation and thermally activated delayed fluorescence which was utilised to test hosting properties of the differently donor-substituted pyrimidine-5-carbonitriles.

Synthesis, characterizations of new Schiff base heterocyclic derivatives and their optoelectronic, computational studies with level II & III features of LFPs

Organic Schiff base compounds with luminous characteristics are receiving attention and increasing demand for the imaging of latent fingerprints (LFPs) at crime scenes. Sb1 and Sb2 novel Schiff base heterocyclic compounds were synthesized and confirmed by using analytical and spectroscopic methods. The existence of both donating and accepting groups influenced the appearance of absorption bands at longer wavelength and was recorded using UV-absorption and emission spectrum in solvent media. Compounds Sb1 and Sb2 emit at 576 nm and 646 nm in bathochromic shift respectively. The electrochemical properties were investigated using cyclic voltammetry. Quantum chemical parameters with vibrational frequency have been estimated in density functional theory (DFT), using TD-DFT/CAM (B3LYP) approach employing 6–311++ G (d, p) basis set in the ground state. Theoretical vibrational frequency values were specifically agreed to obtained experimental values. Furthermore, FMOs, MEPs, RDG analyses and Mulliken atomic charges have been calculated. In addition, LFPs images were developed by powder dusting approach on specified materials using synthetic compounds and visualized under Visible and UV light. The level II and III properties of LFPs on the substrate were observed under light-medium with no background interference, therefore these compounds are potential materials for electroluminescent, OLEDs and forensic science applications.

Donor-Acceptor structured phenylmethylene pyridineacetonitrile derivative with aggregation-induced emission characteristics: photophysical, mechanofluorochromic and electroluminescent properties

Development of organic luminescent materials which are highly emissive in aggregation state is of great significance in practical applications. In this work, a phenylmethylene pyridineacetonitrile derivative fluorophore p-DBCNPy was synthesized via Knoevenagel condensation in good yield and its structure was characterized. p-DBCNPy exhibited evident aggregation-induced emission (AIE) feature and remarkable solvatochromic effect. The solid powder of p-DBCNPy emitted green fluorescence with a quantum yield of 0.59. Taking the advantages of the high emission efficiency and thermal stability, p-DBCNPy was employed as the light emitting material in an organic light-emitting diode (OLED) device and showed good potential in electroluminescent applications. Moreover, the fluorophore demonstrated reversible mechanochromism behavior which was ascribed to the transformation between the crystalline and amorphous phase. The greenish-yellow emission of p-DBCNPy powder turned orange with a red shift of over 40 nm upon grinding. The results demonstrated the versatilities of phenylmethylene pyridineacetonitrile derivatives in the applications in mechanochromism and optoelectronics.