Synthesis, Optical, Electrochemical, DFT Studies, NLO Properties, and Ultrafast Excited State Dynamics of Carbazole-Induced Phthalocyanine Derivatives

Abstract

In this paper, we present results from the detailed investigations on the synthesis, optical, emission, electrochemical, and ultrafast nonlinear optical (NLO) properties along with the excited state dynamics of zinc­(II) 2,10,16,24-tetrakis­(9-phenyl-9H-carbazol-2-yl)­phthalocyanine (CBZPC1) and zinc­(II) 2,10,16,24-tetrakis­(4-(9H-carbazol-9-yl)­phenyl)­phthalocyanine (CBZPC2). Due to the presence of carbazole moieties, the Soret band was found to be broadened. The emission studies performed using different solvents revealed the fluorescence yields in the range of 0.10–0.27 and the time-resolved fluorescence data revealed radiative lifetimes of, typically, a few nanoseconds. Femtosecond transient absorption measurements indicated the formation of triplet states within the first nanosecond of photoexcitation. From the cyclic voltametric studies, the oxidation and reduction processes were found to be ring centered. Spectral changes in the UV–visible absorption were recorded by means of spectro-electrochemical analysis at an applied potential. The DFT and TD-DFT analysis was employed using B3LYP hybrid functional theory and 6-31G­(d,p) basis set in the Gaussian 09 package. The NLO properties of CBZPC1 and CBZPC2 were investigated using the Z-scan technique and femtosecond (fs) pulses with kHz and MHz repetition rates. Closed and open aperture Z-scan data were recorded at three different wavelengths of 600, 700, and 800 nm, and the NLO coefficients were extracted from both types of data. Two-photon absorption (TPA) was the dominant mechanism observed in the open aperture Z-scan data. The real and imaginary parts of the χ(3) along with the two-photon absorption cross sections were evaluated. Our NLO data and large 2PA coefficients and cross sections obtained indicate the potential of these compounds for applications in optical limiting and optical switching applications.

Electrical transport properties and ultrafast optical nonlinearity of rGO–metal chalcogenide ensembles

“…The NLO behavior of rGO-based composites has been reported in the literature. 26,44 For example, Anand et al have investigated the NLO properties of hydrogen exfoliated graphene-Pd composites and reported a NLA coefficient of $ 4.9 Â 10 À4 cm GW À1 with fs excitation. 44 A study has shown a b value of $ 1.8 Â 10 À3 cm GW À1 in exfoliated graphene-CuO hybrid composites in the fs regime.…”

“…24 The nonlinear optical (NLO) properties of GO, rGO and rGOnanomaterial composites have been considerably studied by the scientic community. [25][26][27] The nonlinear optical materials are widely being used in different areas like diversifying lasers, laser mode-lockers, advanced spectroscopy, information technology etc. 28 Pristine graphene with vanishingly small band gaps possesses only saturation absorption (SA).…”

Linear‐Nonlinear Optical and Quantum Chemical Studies on Quinolinium 4‐Aminobenzoate: A Third Order Non‐Linear Optical Material for Optoelectronic Applications

“…In NLO applications, optical limiting is considered as an important phenomenon to permit the transmission of only low intensity radiation restricting the high intensity radiation. [ 55 ] In the measurements, the transmitted fluence is recorded with the input energy tuned using a neutral density filter. The optical limitation response of ABAQ crystal is depicted in Figure .…”

Optoelectronic, femtosecond nonlinear optical properties and excited state dynamics of a triphenyl imidazole induced phthalocyanine derivative

“…All the details of the Z-scan experiments are documented in our earlier works. 46,47 The solutions were placed in a 1 mm cuvette (thickness was less than the Rayleigh range), satisfying the thin-sample approximation during the Z-scan data analysis. The input peak intensities used were 20-60 GW cm À2 and the Rayleigh range was in the 1.9-2.8 mm range for the 700-900 nm spectral window.…”

“…[29][30][31][32][33][34][35] In this regard, our group has also investigated many phthalocyanines to understand the structure and NLO properties correlation for identifying potential molecules for various photonic applications. [36][37][38][39][40][41][42][43][44][45][46][47] over the last few years. To this end our group has been involved in investigating and optimizing the NLO properties of different phthalocyanine, Corrole 37 molecules in the form of thin lms, nanoparticles (NPs) and solutions.…”