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Side-Chain Engineering of Donor–Acceptor Conjugated Small Molecules As Dopant-Free Hole-Transport Materials for Efficient Normal Planar Perovskite Solar Cells
摘要： Simultaneously improving efficiency and stability, which are particularly crucial factors for the commercialization of perovskite solar cells (PSCs), remains a major challenge. For high efficiency normal PSCs, the development of stable dopant-free hole-transport materials (HTMs) seems imperative. Here, we developed potential donor-acceptor (D-A) small molecules (BTTI) as HTMs for normal planar PSCs. Through tailoring its alkyl side chain length as BTTI-C6, BTTI-C8 and BTTI-C12, our results show that upon shortening the side chain of BTTI, the hole mobility, film-forming capability and resultant device performance were remarkably improved, with device conversion efficiencies of 19.69% for BTTI-C6, 18.89% for BTTI-C8 and 17.49% for BTTI-C12. Meanwhile, compared to those made with the routine doped Spiro-OMeTAD, devices based on our dopant-free HTMs exhibited significantly improved stability. This work paves the way to the development of effective dopant-free HTMs for high performance PSCs.
关键词： Perovskite solar cells,Donor-acceptor conjugated small molecules,Dopant-free,Hole-transport materials,Side chain engineering
更新于2025-09-11 14:15:04
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Dihydrophenazine‐based double‐anchoring dye for dye‐sensitized solar cells
摘要： A novel dihydrophenazine-based organic di-anchoring dye DK-11 was synthesized by utilizing a simple synthetic protocol. The dye was characterized by optical and electrochemical studies and used as a sensitizer for dye-sensitized solar cell. The proposed butterfly structure was supported by IR experiments which ensured the binding of both carboxylic acid units on the semiconductor surface. Using the dye DK-11, the device generated an efficiency of 5.07% with JSC, VOC, and FF values of 10.65 mA/cm2, 0.67 V, and 0.71, respectively.
关键词： donor-acceptor dyes,dye-TiO2 binding,molecular geometry,di-anchoring dyes,dye-sensitized solar cells
更新于2025-09-11 14:15:04
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Effects of Pyrazine Derivatives and Substituted Positions on the Photoelectric Properties and Electromemory Performance of D–A–D Series Compounds
摘要： Pyrazine derivatives quinoxaline and pyridopyrazine were selected as the acceptors, and benzocarbazole was used as the donor to synthesize four different D–A–D compounds. The results showed that 2,3-bis(decyloxy)pyridine[3,4-b]pyrazine (DPP) exhibited stronger electron-withdrawing ability than that of 2,3-bis(decyloxy)quinoxaline (DPx), because DPP possesses one more nitrogen (N) atom, resulting in a red-shift of the intramolecular charge transfer (ICT) absorption bands and ?uorescent emission spectra for compounds with DPP as the acceptor compared with those that use DPx as the acceptor. The band-gap energy (Eg) of the four D–A–D compounds were 2.82 eV, 2.70 eV, 2.48 eV, and 2.62 eV, respectively, for BPC-2DPx, BPC-3DPx, BPC-2DPP, and BPC-3DPP. The solvatochromic effect was insigni?cant when the four compounds were in the ground state, which became signi?cant in an excited state. With increasing solvent polarity, a 30–43 nm red shift was observed in the emissive spectra of the compounds. The thermal decomposition temperatures of the four compounds between 436 and 453 ?C had very high thermal stability. Resistor-type memory devices based on BPC-2DPx and BPC-2DPP were fabricated in a simple sandwich con?guration, Al/BPC-2DPx/ITO or Al/BPC-2DPP/ITO. The two devices showed a binary non-volatile ?ash memory, with lower threshold voltages and better repeatability.
关键词： quinoxaline,photoelectric properties,donor-acceptor-donor,pyrazine,electromemory,benzocarbazole
更新于2025-09-10 09:29:36
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Highly Stable and Multifunctional Aza-BODIPY-Based Phototherapeutic Agent for Anticancer Treatment
摘要： Phototherapy, as an important class of noninvasive tumor treatment methods, has attracted extensive research interest. Although a large amount of the near-infrared (NIR) phototherapeutic agents have been reported, the low efficiency, complicated structures, tedious synthetic procedures, and poor photostability limit their practical applications. To solve these problems, herein, a donor?acceptor?donor (D?A?D) type organic phototherapeutic agent (B-3) based on NIR aza-boron-dipyrromethene (aza-BODIPY) dye has been constructed, which shows the enhanced photothermal conversion efficiency and high singlet oxygen generation ability by simultaneously utilizing intramolecular photoinduced electron transfer (IPET) mechanism and heavy atom effects. After facile encapsulation of B-3 by amphiphilic DSPE?mPEG5000 and F108, the formed nanoparticles (B-3 NPs) exhibit the excellent photothermal stabilities and reactive oxygen and nitrogen species (RONS) resistance compared with indocyanine green (ICG) proved for theranostic application. Noteworthily, the B-3 NPs can remain outstanding photothermal conversion efficiency (η = 43.0%) as well as continuous singlet oxygen generation ability upon irradiation under a single-wavelength light. Importantly, B-3 NPs can effectively eliminate the tumors with no recurrence via synergistic photothermal/photodynamic therapy under mild condition. The exploration elaborates the photothermal conversion mechanism of small organic compounds and provides a guidance to develop excellent multifunctional NIR phototherapeutic agents for the promising clinical applications.
关键词： heavy atom effects,intramolecular photoinduced electron transfer,donor?acceptor?donor type,NIR phototherapeutic agents,aza-BODIPY
更新于2025-09-10 09:29:36
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Stereospecific [2+2]-cross-photocycloaddition in a supramolecular donor–acceptor complex
摘要： A bis(propylammonium) derivative of (E)-4-(4-mercaptostyryl)pyridine, which was synthesized for the first time, forms a highly stable bimolecular complex with a bis(18-crown-6 ether) derivative of (E)-stilbene in solution owing to ditopic coordination via hydrogen bonds. The complex formation results in much faster deactivation of the excited states of both compounds, which is explained by photoinduced electron transfer from the stilbene derivative to the styrylpyridinium dye. Despite this, the complexed olefins undergo [2+2]-cross-photocycloaddition upon selective excitation of the dye to afford solely the syn-cycloadduct. The retro-photocycloaddition occurs readily upon UV irradiation of the cycloadduct and leads to the initial bimolecular complex.
关键词： Photoinduced electron transfer,Donor–acceptor systems,Cross-photocycloaddition,Self-assembly
更新于2025-09-10 09:29:36
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Surface with Reversible Green-light-switched Wettability by Donor-Acceptor Stenhouse Adducts
摘要： In this report, we designed surfaces with reversible green-light-switched wettability by Donor-Acceptor Stenhouse adducts (DASAs). Photoresponsive micro/nanoparticles were prepared by coating polydopamine on the surface of silica micro/nanoparticles and then post-modifying with DASA molecules. Then, the particles were immobilized on glass substrates surface either by double-sided adhesive tapes or crosslinking polydimethylsiloxane. Silica micro/nanoparticles with various diameters (0.2, 2.5 and 85 μm) were used to fabricate the photoresponsive surface. Green light irradiation switches the hydrophobic linear DASA to hydrophilic cyclic isomer, which further increases the wettability and contact angle hysteresis on surface. On the other hand, heating (100 oC) induces the cyclic-to-linear isomerization of DASA molecules, and switches the surface back to hydrophobic. The wettability of the DASAs modified surface is reversible under alternately green light irradiating and heating.
关键词： donor-acceptor Stenhouse adducts,green light,surface,photoresponsive system,wettability
更新于2025-09-10 09:29:36
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A novel quinoxaline-based donor-acceptor type electrochromic polymer
摘要： We synthesize a quinoxaline-based novel conjugated donor–acceptor random copolymer containing benzodithiophene and 2,5-difluorophenylenedithiophene units as electron donors (coded r-PQ) and investigate the electrochromic properties of the material. Despite its high molecular weight, r-PQ is highly soluble in organic solvents owing to the side chain of alkoxy at the meta-position of the phenyl ring. The r-PQ film exhibits excellent redox-promoted blue to transmissive-state color switching with high coloration efficiency (>250 cm2/C) and a fast response time (< 0.5 s). These results suggest that our quinoxaline-based random copolymer could be a promising candidate as an organic electrochromic material.
关键词： donor-acceptor type,quinoxaline,random polymer,non-covalent,electrochromic
更新于2025-09-10 09:29:36
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Photo-Physical Properties of Thermally Activated Delayed Fluorescent Materials upon Distortion of Central Axis of Donor Moiety
摘要： In this study, we showed the distortion of central axis of donor moiety can switch critically the rate of reverse intersystem crossing (kRISC) process, which is the trigger point to modulate the lifetime of delayed fluorescence. To achieve kRISC what we desired (105 to 106 s-1) in a series of donor-acceptor-donor (D-A-D) type thermally activated delayed fluorescence (TADF) materials, the donor groups (phenoxazine and phenothiazine) was selectively introduced. Maintaining the near orthogonality between donor and acceptor (benzonitrile) moiety, the occurrence of the distortion of central axis of donor moiety could make the effect of locally excited triplet state (3LE). In other words, the interaction between 3LE and the charge transfer counterparts (i.e., 1CT and 3CT) contributes an opposite propensity of kRISC for each target TADF materials when those are dissolved in solution and condensed in solid-state. Herein, we have theoretically and experimentally shown the photo-physical behavior of common D-A-D type TADF upon the different system.
关键词： Reverse Intersystem Crossing,Thermally Activated Delayed Fluorescence,Benzonitrile,Phenoxazine,Donor-Acceptor-Donor,Phenothiazine
更新于2025-09-09 09:28:46
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Complex Formation of Cobalt(II) Octakis(3,5-di-tert-butylphenoxy)phthalocyanine with 2′-(Pyridin-4-yl)-5′-(Pyridin-2-yl)-1′-(Pyridin-2-ylmethyl)-2′,4′-Dihydro-1′H-Pyrrolo[ 3′,4′:1,2][C60-Ih][5,6]fullerene
摘要： The formation of the donor–acceptor complex of cobalt(II) octakis(3,5-di-tert-butylphenoxy)phthalocyanine with 2'-(pyridin-4-yl)-5'-(pyridin-2-yl)-1'-(pyridin-2-ylmethyl)-2',4'-dihydro-1'H-pyrrolo[3',4':1,2][C60-Ih][5,6]fullerene (Py3C60) in toluene was studied by chemical kinetics (thermodynamics) and spectroscopy methods in comparison with a similar system based on 4-picoline (Pic). In both cases, the reaction occurred in one step giving donor–acceptor complexes of 1 : 1 stoichiometry, which were characterized by key spectral (UV-vis, IR, 1H NMR) parameters and thermodynamic equilibrium parameters; in the case of reaction with pyridyl-substituted fullerene, full kinetic description was obtained. The stability constants for (Pic)CoPc(3,5-tBuPhO)8 and (Py3C60)CoPc(3,5-tBuPhO)8 are (1.01 ± 0.16) × 104 L/mol (logK = 4.00, Δ G = –22.84 kJ/mol) and (1.84 ± 0.16) × 105 L/mol (logK = 5.26, Δ G = –30.04 kJ/mol), respectively. The obtained results are relevant for the development of new efficient components for photovoltaic cells based on phthalocyanine–fullerene systems.
关键词： 4-picoline,thermodynamics,phthalocyanine–fullerene complex,kinetics,donor–acceptor complex formation,pyridyl-fullerene,spectral properties,cobalt(II) phthalocyanine
更新于2025-09-09 09:28:46
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Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes
摘要： A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.
关键词： ambipolar,Donor-Acceptor,Thermally Activated Delayed Fluorescence,exciplex,Organic Electronics,patterning,thermal evaporation,Issue 141,OLED,Engineering
更新于2025-09-09 09:28:46