Highly efficient luminescence from hybrid structures of ZnO/multi-walled carbon nanotubes for high performance display applications

Grover, Vaneet; Gupta, Govind; Shanker, Virendra

doi:10.1088/0957-4484/21/47/475701

Cited by 20 publications

(9 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When incorporated in the CNTs composite, the surface of the TP is in direct contact with the functionalized CNTs which could lead to a higher concentration of electron-hole pairs in the surface of the TPs. The enhancement of the PL intensity in ZnO/CNT composites was previously reported in the literature [19,35] due to the generation of a higher concentration of optically active defects in the mentioned spectral region, namely improving surface and excitonic related recombination.…”

Section: Resultssupporting

confidence: 59%

“…Constituting a functional component in various applications buckypapers can be used as permeable membranes, capacitors, electrodes for fuel cells, reinforcement in composite materials, among others [30][31][32][33][34]. This approach could be used as an effective method to create composites of CNTs with metal oxide nanoparticles with suitable properties to give rise new materials with tailoring properties [29,35]. ZnO appears as a good candidate to be incorporated in CNT buckypapers since this material enlarges the photon absorption region, increasing the photoconversion efficiency of the generated photocurrent [29].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

One-step synthesis of ZnO decorated CNT buckypaper composites and their optical and electrical properties

Rodrigues

Mata

Pimentel

et al. 2015

Materials Science and Engineering: B

View full text Add to dashboard Cite

a b s t r a c tZnO/CNT composites were prepared using ZnO nanoparticles and tetrapods synthesized by the Laser Assisted Flow Deposition method. The co-operative behaviour between these two materials may give rise to the production of advanced functional materials with a wide range of applications in electronics and optoelectronics. Despite some degree of aggregation in the case of the nanoparticles, scanning electron microscopy images evidence that the produced ZnO structures are well dispersed in the CNT buckypapers. Independent of the ZnO morphology the samples resistivity was shown to be of the order of ∼10 −1 cm while in the case of the electron mobility, the composite with tetrapods reveals a lower value than the ones obtained for the remaining samples. Well-structured ZnO luminescence was observed mainly in ultraviolet highlighting the high optical quality of the produced structures. The temperature dependence of the luminescence reveals a distinct trend for the composites with ZnO tetrapods and ZnO nanoparticles.

show abstract

Section: Resultssupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

One-step synthesis of ZnO decorated CNT buckypaper composites and their optical and electrical properties

Rodrigues

Mata

Pimentel

et al. 2015

Materials Science and Engineering: B

View full text Add to dashboard Cite

show abstract

“…In this case, only a small enhancement in the overall luminescence was observed without any change in the shape of the emission (Figure 15). This observation, also reported by others 76 , 77 has been explained on the basis of the increase of the optical centers concentration from where the luminescence is originated due to the high surface to volume ratio 77 , suggesting that for the CNT samples an enhancement of the intrinsic carriers is promoted with above band gap excitation leading to a higher luminescence intensity 33 . On the contrary, the ZnO/CNTs buckypapers shown in this work, do not exhibit the usual deep level emission and the ultraviolet band evidences noticed changes before and after embedding the ZnO structures in the CNTs.…”

supporting

confidence: 76%

ZnO micro/nanocrystals grown by laser assisted flow deposition

et al. 2014

View full text Add to dashboard Cite

Laser assisted flow deposition (LAFD) is a very high yield method based on a vapor-solid mechanism, allowing the production of ZnO crystals in a very short time. The LAFD was used in the growth of different morphologies (nanoparticles, tetrapods and microrods) of ZnO micro/nanocrystals and their microstructural characterization confirms the excellent crystallinity of the wurtzite structure. The optical properties of the as-grown ZnO crystals investigated by low temperature photoluminescence (PL) evidence a well-structured near band edge emission (NBE) due to the recombination of free (FX), surface (SX) and donor bound (D 0 X) excitons. Among the most representative emission lines, the 3.31 eV transition was found to occur in the stacking faults-free microrods. The luminescence behavior observed in H passivated samples suggests a closer relationship between this optical center and the presence of surface states.Besides the unintentionally doped micro/nanocrystals, ZnO/Ag and ZnO/carbon nanotubes (CNT) hybrid structures were processed by LAFD. The former aims at the incorporation of silver as a p-type dopant and the latter envisaging photovoltaic applications. Silver-related spherical particles were found to be inhomogeneously distributed at the microrods surface, accumulating at the rods tips and promoting the ZnO nanorods re-nucleation. Despite the fact that energy dispersive X-ray measurements suggest that a fraction of the silver could be incorporated in the ZnO rods, no new related luminescence lines or bands were observed when compared with the as-grown samples. For the case of the ZnO/CNT composites two main approaches were adopted: i) a direct deposition of ZnO particles on the surface of vertically aligned multi-walled carbon nanotubes (VACNTs) forests without employing any additional catalyst and ii) new ZnO/CNT hybrids were developed as buckypaper nanocomposites. The use of the LAFD technique in the first approach preserves the CNTs structure and alignment and avoids the collapse of the VACNTs array, which is a major advantage of this method. On the other hand, LAFD grown ZnO nanoparticles and tetrapods were used to produce ZnO/CNT buckypaper nanocomposites. When compared with the as-grown samples the PL spectra of the composites structures behave differently. For the case of the ZnO/VACNTs no changes on the peak position and spectral shape were observed. Only an enhancement of the overall luminescence was found to occur. On contrary, for the buckypaper nanocomposites notable changes on the spectral shape and peak position were observed, likely due to distinct surface band bending effects for the ZnO nanoparticles and tetrapods embedded in the CNTs.

show abstract

“…As compared to TiO 2 particles, the PL intensity of the PPY composites containing TiO 2 and MLG is significantly decreased. This is due to the fact that the PPY is a p-type narrowbandgap semiconductor polymer and PPY has a quenching effect, which decreases the PL intensity with the increase of its concentration [17,18]. It is interesting to note that the PL intensity of PPY/0.05MLG/0.05TiO 2 composite is more than the PPY/0.05TiO 2 composite.…”

Section: Resultsmentioning

confidence: 98%

Enhanced electromagnetic shielding behaviour of multilayer graphene anchored luminescent TiO2 in PPY matrix

Gupta

Varshney²,

Goyal

et al. 2015

Materials Letters

View full text Add to dashboard Cite

Highly efficient luminescence from hybrid structures of ZnO/multi-walled carbon nanotubes for high performance display applications

Cited by 20 publications

References 21 publications

One-step synthesis of ZnO decorated CNT buckypaper composites and their optical and electrical properties

One-step synthesis of ZnO decorated CNT buckypaper composites and their optical and electrical properties

ZnO micro/nanocrystals grown by laser assisted flow deposition

Enhanced electromagnetic shielding behaviour of multilayer graphene anchored luminescent TiO2 in PPY matrix

Contact Info

Product

Resources

About