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1.
《Chemphyschem》2003,4(4):349-358
The light generating mechanism of a series of light emitting diodes with electron donor–bridge–acceptor systems (D–b–A) as the emitting species was examined by constructing model diodes based on small organic molecules (OLEDs) as well as on molecularly doped electroactive (poly‐N‐vinylcarbazole, PVK) and insulating (polystyrene, PS) polymers (PLEDs). The direct electrogeneration of an intramolecular charge‐transfer (CT) fluorescence of the donor–bridge–acceptor systems occurred readily in OLED devices with a D–b–A system as the emissive layer. In diodes with PS as the host matrix, hole‐injection and electron‐injection occurred directly in the D–b–A molecules residing close to the anode and the cathode, respectively. In the PVK diodes, hole‐injection occurred primarily into PVK and the positive charge carrier was subsequently trapped on the D–b–A molecule, whereas electron‐injection at the cathode side occurred directly into the D–b–A molecules. Charge‐hopping between neighboring molecules then occurred until a hole and electron resided on the same molecule, which is equivalent to the formation of the CT excited state, and which finally relaxed by intramolecular charge recombination under the emission of CT fluorescence. 相似文献
2.
Jicheol Shin Hyun Ah Um Min Ju Cho Tae Wan Lee Kyung Hwan Kim Jung‐Il Jin Seogshin Kang Taehan Park Sung Hoon Joo Joong Hwan Yang Dong Hoon Choi 《Journal of polymer science. Part A, Polymer chemistry》2012,50(2):388-399
A hole‐injection/transport bilayer structure on an indium tin oxide (ITO) layer was fabricated using two photocrosslinkable polymers with different molecular energy levels. Two photoreactive polymers were synthesized using 2,7‐(or 3,6‐)‐dibromo‐9‐(6‐((3‐methyloxetan‐3‐yl)methoxy)hexyl)‐9H‐carbazole) and 2,4‐dimethyl‐N,N‐bis(4‐ (4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)aniline via a Suzuki coupling reaction. When the oxetane groups were photopolymerized in the presence of a cationic photoinitiator, the photocured film showed good solvent resistance and compatibility with a poly(N‐vinylcarbazole) (PVK)‐based emitting layer. Without the use of a conventional hole injection layer (HIL) of poly(3,4‐ethylenedioxythiophene)/(polystyrenesulfonate) (PEDOT:PSS), the resulting green light‐emitting device bearing PVK: 5‐4‐tert‐butylphenyl‐1,3,4‐oxadiazole (PBD):Ir(Cz‐ppy)3 exhibited a maximum external quantum efficiency of 9.69%; this corresponds to a luminous efficiency of 29.57 cd/A for the device K‐4 configuration ITO/POx‐I/POx‐II/PVK:PBD:Ir(Cz‐ppy)3/triazole/Alq3/LiF/Al. These values are much higher than those of PLEDs using conventional PEDOT:PSS as a single HIL. The significant improvement in device efficiency is the result of suppression of the hole injection/transport properties through double‐layered photocrosslinked‐conjugated polymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
3.
Carbazole end‐capped pyrene starburst with enhanced electrochemical stability and device performance
Feng Liu Jian‐hua Zou Qi‐yuan He Chao Tang Ling‐hai Xie Bo Peng Wei Wei Yong Cao Wei Huang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(22):4943-4949
Carbazole end‐capped starburst molecule based on pyrene core “4CzFP” was synthesized and characterized. The starburst material shows good film‐forming ability and bright blue fluorescence. In cyclic voltammetry test, 4CzFP shows a high highest occupied molecular orbital energy level of ?5.26 eV, indicating it has good hole‐injection ability. The material is quite stable under series of cyclic voltammetry scans, implying its good electrochemical stability. Single‐layered electroluminescent device takes on stable blue emission with a peak current efficiency of 0.84 cd/A. Double‐layered device by adding Poly(N‐vinylcarbazole) (PVK) as a hole‐injection layer does not show any improvement, indicating that 4CzFP could be efficiently used as the hole‐injection/light‐emitting layer. The device performance is largely improved by adding a thin TPBI electron‐injection/transporting layer. The peak efficiency reaches 3.28 cd/A and the maximum brightness is over 2200 cd/m2. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
4.
A soluble and thermally stable arylamine oligomer containing difluorenyl groups was prepared and applied to organic light‐emitting devices (OLEDs) as a hole injection layer. The oligomer layer was doped with a Lewis acid and formed by spin coating from the dichloroethane solution. The OLED with a structure of indium tin oxide (ITO)/Lewis‐acid‐doped arylamine oligomer/N,N′‐dinaphthyl‐N,N′‐diphenyl bendizine (α‐NPD)/tris(8‐quinolinolato)aluminum(III) (Alq3)/LiF/Al showed lower drive voltages and higher power efficiencies, compared with the devices without the hole injection oligomer layer. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
5.
Dr. Jin Young Park Dong‐Eun Kim Dr. Ramakrishna Ponnapati Prof. Jong‐Min Kim Prof. Young‐Soo Kwon Prof. Rigoberto C. Advincula 《Chemphyschem》2011,12(5):1010-1015
The electroluminescent (EL) properties of a cross‐linkable carbazole‐terminated poly(benzyl ether) dendrimer, G3‐cbz DN, doped into a PVK:PBD host matrix with a double‐layer device configuration are investigated. Different concentrations of the guest material can control device efficiency, related to chromaticity of white emission and the origin of excited‐state complexes occurring between hole‐transporting carbazole units (PVK or G3‐cbz DN) and electron‐transporting oxadiazole (PBD). Two excited states (exciplex and electroplex) generated at the interfaces of PVK/G3‐cbz DN and PBD result in competitive emission, exhibiting a broad band in the EL spectra. 相似文献
6.
High efficiency organic light‐emitting‐devices (OLED) have been fabricated by incorporation of a polymeric layer as a controller of the unbalanced charge. In device configuration of ITO/PEDOT:PSS/PVK/Alq3/LiF:Al, poly(N‐vinylcarbazole) (PVK) was selected as a block‐ing layer (BL) because it has a hole transporting property and a higher band gap, especially a lower LUMO level than the emitting layer (Alq3) and a higher HOMO level than the hole injection layer (PEDOT: PSS). As a result, the optimal structure with this bl layer showed a peak efficiency of 6.89 cd/A and 2.30 lm/W compared to the device without the PVK layer of 1.08 cd/A, 0.27 lm/W. This result shows that the PVK layer could effec‐tively block the electrons from metal cathode and confine them in the emitting layer and accomplish the charge balance, which leads to enhanced hole‐electron balance for achieving high recombination efficiency. 相似文献
7.
María A. Díaz‐García 《Journal of Polymer Science.Polymer Physics》2003,41(21):2706-2714
We investigated the lasing properties of optically pumped polymer films. Amplified spontaneous emission (ASE) around 400 nm was observed in polymer films of polystyrene (PS) and poly(N‐vinylcarbazole) (PVK) doped up to 20% with the hole‐transporting organic molecule N,N′‐bis(3‐methylphenyl)‐N,N′‐diphenylbenzidine (TPD). Thus, TPD‐based films are candidates for blue‐emitting organic diode lasers. Films containing several semiconducting organic molecules and polymers and rare‐earth complexes were also investigated. Energy transfer was observed in PVK films doped with various europium and samarium complexes. PS films containing the electron‐transporting organic molecule 2‐(4‐biphenylyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole and small amounts of TPD also showed energy transfer to the europium complexes, but not to the samarium ones. None of these films demonstrated ASE; therefore, they are not appropriate for lasing purposes. However, because rare‐earth ions have very sharp emission spectra, these materials are candidates for very monochromatic light‐emitting diodes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2706–2714, 2003 相似文献
8.
Eunhee Lim Byung‐Jun Jung Hong‐Ku Shim 《Journal of polymer science. Part A, Polymer chemistry》2006,44(1):243-253
New electroluminescent polymers (poly(9,9′‐dioctylfluorene‐co‐thieno[3,2‐b]thiophene‐co‐benzo[2,3,5]thiadiazole) ( P1) and poly(9,9′‐dioctylfluorene‐co‐thieno[3,2‐b]thiophene‐co‐benzo[2,3,5]thiadiazole‐co‐[4‐(2‐ethylhexyloxyl)phenyl]diphenylamine ( P2) ) possess hole‐transporting or electron‐transporting units or both in the main chains. Electron‐deficient benzothiadiazole and electron‐rich triphenylamine moieties were incorporated into the polymer backbone to improve the electron‐transporting and hole‐transporting characteristics, respectively. P1 and P2 show greater solubility than poly(9,9′‐dioctylfluorene‐co‐thieno[3,2‐b]thiophene ( PFTT ), without sacrificing their good thermal stability. Moreover, owing to the incorporation of the electron‐deficient benzothiadiazole unit, P1 and P2 exhibit remarkably lower LUMO levels than PFTT , and thus, it should facilitate the electron injection into the polymer layer from the cathode electrode. Consequently, because of the balance of charge mobility, LED devices based on P1 and P2 exhibit greater brightness and efficiency (up to 3000 cd/m2 and 1.35 cd/A) than devices that use the pristine PFTT . © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 243–253, 2006 相似文献
9.
Hong‐Cheu Lin Chien‐Min Tsai Yu‐Tai Tao 《Journal of polymer science. Part A, Polymer chemistry》2006,44(9):2922-2936
A series of multilayer polymeric light‐emitting diodes (PLEDs) containing an electron‐transporting layer (ETL), that is tris(8‐quinolinolato)‐aluminum(III) (Alq) and 2,2′,2″‐(1,3,5‐phenylene)‐tris[1‐phenyl‐1H‐benzimidazole] (TPBI), were fabricated by doping fluorescent oligo(p‐phenylene‐vinylene)s (BIII and BV) and polymer derivatives (PBV) into poly(N‐vinyl carbazole) (PVK). These PLEDs can be optimized by the design of multilayer device configurations (brightness increased 8–15 times by addition of ETL) and possess greenish electroluminescent (EL) spectra peaked about 500–540 nm. A remarkably high brightness of 56,935 cd/m2 with a power efficiency of 3.25 lm/W was obtained in the device of PVK:BVOC8‐OC8 (100:20)/Alq (60 nm/60 nm). It suggests that the emission mechanism (including the conjugated and excimer emissions of BVOC8‐OC8 emitters) originates from both of BVOC8‐OC8 and ETL (Alq and TPBI) by varying the concentration of chromophores and adjusting the thickness of ETL. The concentration effect of the emitters in PVK (i.e. PVK:BVOC8‐OC8 = 100:5, 100:20, and 100:100 wt %) and the influence of the ETL (including its thickness) on the EL characteristics are also reported. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2922–2936, 2006 相似文献
10.
Paolo Vacca Maria Grazia Maglione Carla Minarini Giovanna Salzillo Eugenio Amendola Dario Della Sala Alfredo Rubino 《Macromolecular Symposia》2005,228(1):263-272
In order to optimize polymer light emitting diode (PLED) performances, devices with holes injected through an Indium Tin Oxide (ITO) / Polyaniline (PANI) electrode into the polymer are much more efficient than devices fabricated with the anode made only by ITO. We demonstrated that by using doped PANI as hole injection layer in a polymer light emitting diode the manufacturing process can become simpler. Indeed, the pattern of conductive layer can be produced without ITO photolithography by UV exposition. As hole transporter layer, Poly(N-vinylcarbazole) (PVK) was spin coated over the doped PANI layer and a layer of tris (8-hydroxy) quinoline aluminum (Alq3) was then thermally evaporated so as to form the electron transport layer. To complete the device structure, Aluminum contacts were deposited onto the organic layers by vacuum evaporation at low pressure. The layers were characterized by X-ray small-angle diffraction, IR Raman and UV-Vis spectroscopies. Devices without PANI and with PANI as HIL were studied. 相似文献
11.
Francisco Núñez‐Zarur Eduardo Arguello Ricardo Vivas‐Reyes 《International journal of quantum chemistry》2010,110(9):1622-1636
The electronic structure and reactivity trends of a set of tris‐(n‐methyl‐8‐quinolinolato) metal (III) (n = 0, 3, 4, 5; metal = Al+3, Ga+3) used as electron‐transport layer in organic light‐emitting diodes were studied and compared. All geometries were optimized at B3LYP/6‐31G(d,p) level of theory. The geometries of the ground state (S0) of unsubstituted molecules AlQ3 and GaQ3 were found to be slightly affected by the methyl group, which is in agreement with previous works. Methyl‐derivatives conserve largely the electronic structures of AlQ3 and GaQ3. The energies of the frontier orbitals highest occupied and lowest unoccupied molecular orbital are raised by the electron‐releasing effect of methyl group. Molecular orbital contribution analysis reveals that the orbital population is essentially the same for both MQ3 and their derivatives. Analyses of the ionization potential and electron affinity showed that MQ3 tend to be better hole‐blockers than methylated analogues and 5Me‐MQ3 have higher hole‐injection capability than the other methyl‐substituted derivatives. The global reactivity analysis showed that the electrophilicity index can be an indicator of electron‐injection capability in these complexes. Local reactivity analysis showed that atomic sites that are prone to nucleophilic/electrophilic attack are atoms C‐4 in L3/C‐5 in L1. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
12.
Chia‐Shing Wu Ya‐Ju Yang Szu‐Wen Fang Yun Chen 《Journal of polymer science. Part A, Polymer chemistry》2012,50(18):3875-3884
This study reports the synthesis, curing, and optoelectronic properties of a solution‐processable, thermally cross‐linkable electron‐ and hole‐blocking material containing fluorene‐core and three periphery N‐phenyl‐N‐(4‐vinylphenyl)benzeneamine ( FTV ). The FTV exhibited good thermal stability with Td above 478 °C in nitrogen atmosphere. The FTV is readily cross‐linked via terminal vinyl groups by heating at 160 °C for 30 min to obtain homogeneous film with excellent solvent resistance. Multilayer PLED device [ITO/PEDOT:PSS/cured‐ FTV /MEH‐PPV/Ca (50 nm)/Al (100 nm)] was successfully fabricated using solution processed. Inserting cured‐ FTV is between PEDOT:PSS and MEH‐PPV results in simultaneous reduction in hole injection from PEDOT:PSS to MEH‐PPV and blocking in electron transport from MEH‐PPV to anode. The maximum luminance and maximum current efficiency were enhanced from 1810 and 0.27 to 4640 cd/m2 and 1.08 cd/A, respectively, after inserting cured‐ FTV layer. Current results demonstrate that the thermally cross‐linkable FTV enhances not only device efficiency but also film homogeneity after thermal curing. FTV is a promising electron‐ and hole‐blocking material applicable for the fabrication of multilayer PLEDs based on PPV derivatives. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 000: 000–000, 2012 相似文献
13.
Wen‐Fen Su Ruei‐Tang Chen Yun Chen 《Journal of polymer science. Part A, Polymer chemistry》2011,49(2):352-360
This article reports the synthesis and characterization of a novel thermally crosslinkable hole‐transporting poly (fluorene‐co‐triphenylamine) (PFO‐TPA) by Suzuki coupling reaction, followed with its application in the fabrication of multilayer light‐emitting diodes by wet processes. The thermal, photophysical, and electrochemical properties of PFO‐TPA were investigated by differential scanning calorimeter, thermogravimetric analysis, optical spectroscopy, and cyclic voltammetry, respectively. Thermally crosslinked PFO‐TPA, through pendant styryl groups, demonstrates excellent thermal stability (Td > 400 °C, Tg = 152 °C), solvent resistance, and film homogeneity. Its highest occupied molecular orbital level (?5.30 eV) lies between those of PEDOT:PSS (?5.0 ~ ?5.2 eV) and poly(9,9‐dioctylfluorene) (PFO: ?5.70 eV), forming a stepwise energy ladder to facilitate hole injection. Multilayer device with crosslinked PFO‐TPA as hole‐injection layer (HIL) (ITO/PEDOT:PSS/HIL/PFO/LiF/Ca/Al) was readily fabricated by successive spin‐coating processes, its maximum luminance efficiency (3.16 cd/A) were about six times higher than those without PFO‐TPA layer (0.50 cd/A). The result of hole‐only device also confirmed hole‐injection and hole‐transport abilities of crosslinked PFO‐TPA layer. Consequently, the device performance enhancement is attributed to more balanced charges injection in the presence of crosslinked PFO‐TPA layer. The thermally crosslinkable PFO‐TPA is a promising material for the fabrication of efficient multilayer polymer light‐emitting diodes because it is not only a hole‐transporting polymer but also thermally crosslinkable. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
14.
CuSbS2‐Sensitized Inorganic–Organic Heterojunction Solar Cells Fabricated Using a Metal–Thiourea Complex Solution 下载免费PDF全文
Dr. Yong Chan Choi Eun Joo Yeom Prof. Tae Kyu Ahn Prof. Sang Il Seok 《Angewandte Chemie (International ed. in English)》2015,54(13):4005-4009
The device performance of sensitizer‐architecture solar cells based on a CuSbS2 light sensitizer is presented. The device consists of F‐doped SnO2 substrate/TiO2 blocking layer/mesoporous TiO2/CuSbS2/hole‐transporting material/Au electrode. The CuSbS2 was deposited by repeated cycles of spin coating of a Cu‐Sb‐thiourea complex solution and thermal decomposition, followed by annealing in Ar at 500 °C. Poly(2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)) (PCPDTBT) was used as the hole‐transporting material. The best‐performing cell exhibited a 3.1 % device efficiency, with a short‐circuit current density of 21.5 mA cm?2, an open‐circuit voltage of 304 mV, and a fill factor of 46.8 %. 相似文献
15.
Manabu Yoshida Manabu Ayano Norihisa Kobayashi 《Journal of Polymer Science.Polymer Physics》2000,38(3):362-368
The structurally ordered polymer, triphenylamine‐pendant polypeptide (PATPA: poly[γ‐4‐(N,N‐diphenylamino‐phenyl)‐L ‐glutamine]), was prepared in order to obtain high hole mobility and high thermal stability. The hole mobility obtained for PATPA (ca. 10−5 cm2/Vsec) at room temperature is higher than that for poly(N‐vinylcarbazole) (PVK) (ca. 10−7 cm2/Vsec) or that of carbazole‐pendant polypeptide (PCLG) (ca. 10−8 cm2/Vsec). These results are supported by thermally stimulated current (TSC) measurements because the TSC can be correlated with the mobility. The glass‐transition temperature (Tg) of PATPA was estimated to be about 130° by differential scanning calorimetry (DSC). From these results, PATPA is an alternative candidate as a photoconductive polymer with high thermal stability and high hole mobility. The ordered structure along the main chain is thought to facilitate hole transport. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 362–368, 2000 相似文献
16.
Novel F‐doped Ag/AgBr photocatalysts containing various amounts of F? were synthesized by an ion exchange method. The photocatalysts were characterized using X‐ray diffraction (XRD), scanning and transmission electron microscopies, X‐ray photoelectron, ultraviolet–visible absorption and photoluminescence spectroscopies and electron spin resonance (ESR). Powder XRD revealed that F? was inserted into the crystal lattices of AgBr and partially replaced Br?, resulting in the contraction of the AgBr lattices. Methyl orange photodegradation experiments showed that the photocatalytic activity of F‐doped Ag/AgBr was significantly dependent on the amount of F?. Ag/AgBr doped with 0.02 M F? achieved the highest activity of 91% after 8 min. ESR showed the main active species in methyl orange degradation was ?OH. The main enhancement mechanism is that F? inhibits the recombination of electron–hole pairs. 相似文献
17.
In this paper, the electroluminescent properties of a new partially‐conjugated hyperbranched poly (p‐phenylene vinylene) (HPPV) were studied. The single layer light‐emitting device with HPPV as the emitting layer emits blue‐green light at 496 nm, with a luminance of 160 cd/m2 at 9 V, a turn‐on voltage of 4.3 V and an electroluminescent efficiency of 0.028 cd/A. By doping an electron‐transport material [2‐(4‐biphenylyl)‐5‐phenyl‐1,3,4‐oxadiazole, PBD] into the emitting layer and inserting a thin layer of tris(8‐hydroxy‐quinoline)aluminum (Alq3) as electron transporting/hole blocking layer for the devices, the electroluminescent efficiency of 1.42 cd/A and luminance of 1700 cd/m2 were achieved. The results demonstrate that the devices with the hyperbranched polymers as emitting material can achieve high efficiency through optimization of device structures. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
18.
A Titanium‐Doped SiOx Passivation Layer for Greatly Enhanced Performance of a Hematite‐Based Photoelectrochemical System 下载免费PDF全文
Dr. Hyo‐Jin Ahn Ki‐Yong Yoon Myung‐Jun Kwak Prof. Ji‐Hyun Jang 《Angewandte Chemie (International ed. in English)》2016,55(34):9922-9926
This study introduces an in situ fabrication of nanoporous hematite with a Ti‐doped SiOx passivation layer for a high‐performance water‐splitting system. The nanoporous hematite with a Ti‐doped SiOx layer (Ti‐(SiOx/np‐Fe2O3)) has a photocurrent density of 2.44 mA cm?2 at 1.23 VRHE and 3.70 mA cm?2 at 1.50 VRHE. When a cobalt phosphate co‐catalyst was applied to Ti‐(SiOx/np‐Fe2O3), the photocurrent density reached 3.19 mA cm?2 at 1.23 VRHE with stability, which shows great potential of the use of the Ti‐doped SiOx layer with a synergistic effect of decreased charge recombination, the increased number of active sites, and the reduced hole‐diffusion pathway from the hematite to the electrolyte. 相似文献
19.
Shang‐Hui Ye Cheng‐Rong Yin Zhou Zhou Tian‐Qing Hu Yong‐Hua Li Lu Li Ling‐Hai Xie Wei Huang 《Journal of Polymer Science.Polymer Physics》2014,52(8):587-595
A blue fluorescent polymer based on poly(vinyl carbazole) (PVK) and terfluorene, combined to make a chemical hybrid at the carbazole unit (PVK‐TF), is fully characterized in this study. PVK‐TF shows useful emission features, such as peaks at 400, 420, 437, 460, and 496 nm, depending on the processing conditions. It possesses a relatively high triplet energy level (2.23 eV), electrochemical stability, good film‐forming ability, and morphological stability. Based on this blue fluorescent material, highly efficient orange phosphorescent polymer light‐emitting diodes (PLEDs) were fabricated with a maximum efficiency of 21.99 cd A?1, and a maximum luminance of 19552.3 cd m?2. Single‐layer hybrid white PLEDs were developed, with a high color rendering index of 81.9 that emitted across the whole visible spectrum from 380 to 780 nm, corresponding to the Commission International de L'Eclairage coordinates x, y values of around (0.38, 0.40) and CCT = 3774, with a maximum current efficiency of 10.69 cd A?1, and a maximum brightness of 15723.3 cd m?2. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 587–595 相似文献
20.
Covalent Modification of MoS2 with Poly(N‐vinylcarbazole) for Solid‐State Broadband Optical Limiters 下载免费PDF全文
Hongxia Cheng Dr. Ningning Dong Ting Bai Yi Song Prof. Jun Wang Yuanhao Qin Dr. Bin Zhang Prof. Yu Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4500-4507
New soluble MoS2 nanosheets covalently functionalized with poly(N‐vinylcarbazole) (MoS2–PVK) were in situ synthesized for the first time. In contrast to MoS2 and MoS2/PVK blends, both the solution of MoS2–PVK in DMF and MoS2–PVK/poly(methyl methacrylate) (PMMA) film show superior nonlinear optical and optical limiting responses. The MoS2–PVK/PMMA film shows the largest nonlinear coefficients (βeff) of about 917 cm GW?1 at λ=532 nm (cf. 100.69 cm GW?1 for MoS2/PMMA and 125.12 cm GW?1 for MoS2/PVK/PMMA) and about 461 cm GW?1 at λ=1064 nm (cf. ?48.92 cm GW?1 for MoS2/PMMA and 147.56 cm GW?1 for MoS2/PVK/PMMA). A larger optical limiting effect, with thresholds of about 0.3 GW cm?2 at λ=532 nm and about 0.5 GW cm?2 at λ=1064 nm, was also achieved from the MoS2–PVK/PMMA film. These values are among the highest reported for MoS2‐based nonlinear optical materials. These results show that covalent functionalization of MoS2 with polymers is an effective way to improve nonlinear optical responses for efficient optical limiting devices. 相似文献