Efficient ultrafast optical limiting using single walled carbon nanotubes functionalized noncovalently with free base and metalloporphyrins

Abstract

The present work is on the linear and third order nonlinear optical properties of single walled carbon nanotubes functionalized noncovalently with free base porphyrin and a metalloporphyrin separately. The functionalized carbon nanotubes (CNTs) are soluble in dimethylformamide, and the microscopic images show that the porphyrin molecules are attached to the surface of the CNTs. The interaction between CNTs and porphyrins is noncovalent and probably due to π-π interaction as both CNTs and porphyrins have π-electron rich structures. The samples exhibit large ultrafast nonlinear absorption as evident from the open aperture z-scan studies performed using mode-locked Ti:Sapphire femtosecond pulses at 780 nm. The mechanisms of optical nonlinearity of the functionalized CNTs appear to be two photon absorption along with nonlinear scattering with a small contribution from saturable absorption, whereas nonfunctionalized CNTs are known to exhibit saturable absorption. The value of the nonlinear absorption coefficient for the CNTs functionalized with the free base porphyrin is one order smaller than that for CNTs functionalized with metalloporphyrin. Efficient low threshold ultrafast optical limiting is demonstrated for both types of functionalized CNTs.

MoS2/Carbon Nanotube Core–Shell Nanocomposites for Enhanced Nonlinear Optical Performance

“…[3,38,39] According to previousw ork, the OL effects of MoS 2 and CNTsc an be ascribed to TPA, [26] RSA and/or free carrier absorption, [39][40][41] respectively,asn onlinear scattering can be neglected under femtosecondr egime using low-intensityp ulses. [43,44] Thus in the following discussion, we mainlyf ocus on samples MoS 2 -L/ CNTsand pure CNTs. As shown in Figure 4, the sample MoS 2 -L/CNTss hows mainly an SA response with an OL response generating as the sample moves along the z-axis to the focus point, similar to that of pure CNTs.…”

“…The better SA response of MoS 2 -L/ CNTsc ompared to pure CNTss uggestst hat there is as trong interaction between CNTsa nd the few-layer MoS 2 in the nanocomposites. [43,44] Thus in the following discussion, we mainlyf ocus on samples MoS 2 -L/ CNTsand pure CNTs. To investigate in detail the effect of MoS 2 on the NLO of CNTs, the NLO performance of MoS 2 -L/CNTs was comparedw ith that of pure CNTsi nt hree different states at 1030 nm (340 fs).…”

“…As shown in Figure , the sample MoS 2 ‐L/CNTs shows mainly an SA response with an OL response generating as the sample moves along the z ‐axis to the focus point, similar to that of pure CNTs. The better SA response of MoS 2 ‐L/CNTs compared to pure CNTs suggests that there is a strong interaction between CNTs and the few‐layer MoS 2 in the nanocomposites . Thus in the following discussion, we mainly focus on samples MoS 2 ‐L/CNTs and pure CNTs.…”

Strong π-π interaction of porphyrins on (6,5) carbon nanotubes with full surface coverage: Ab-initio calculations

“…Indeed, porphyrin-CNT complexes have been widely investigated for optoelectronic applications. [1][2][3][4][5][6][7][8][9][10] Recently, Vialla et al 11 have investigated the chirality dependence of the absorption cross section of semiconducting CNTs by noncovalent functionalization with free-base tetraphenylporphyrin (TPP) molecules, taking advantage of the extremely efficient energy transfer observed in the CNT-TPP compounds. 5 In that work, the number of adhered TPPs on CNTs with a diameter of about 8 Å that fit its circumference was assumed to be three per unit length.…”

Single- and double-wall carbon nanotubes fully covered with tetraphenylporphyrins: Stability and optoelectronic properties from ab initio calculations

“…This supramolecular assembly has been explored recently as light-harvesting donor/acceptor complexes [1][2][3][4][5][6][7][8][9][10] , as well as for the electrocatalysis of the oxygen reduction reaction [11][12][13][14] . Some schemes proposed for the such a functionalization include the CNT encapsulation in micelles of surfactant 15 or in polymers.…”