Tetrabrominated Lead Naphthalocyanine for Optical Power Limiting

Abstract

The complex 2,(3)-tetrabromo-3,(2)-tetra[(3,5-di-tert-butyl)phenyloxy]-naphthalocyaninato lead [Br(4)(tBu(2)C(6)H(3)O)(4)NcPb, 1] has been prepared and its optical limiting properties for ns light pulses have been measured. Complex 1 behaves as a reverse saturable absorber within the spectral range 440-720 nm with a limiting threshold of 0.1 J cm(-2) at 532 nm. The lifetime of the absorbing triplet excited state has been evaluated as 3.8 x 10(-7) s and the quantum yield of triplet formation has been measured as 0.07 in toluene. The nonlinear optical transmission properties of complex 1 have also been determined in Plexiglas [naphthalocyanine content: 5.0 x 10(-4) M (0.1% by weight)]. A reversible nonlinear absorption was again observed for a fluence above 0.4 J cm(-2), but through different excited-state dynamics. This may be rationalized in terms of aggregation of the molecule in the polymer matrix.

Electrochemically Deposited NiO Films as a Blocking Layer in p-Type Dye-Sensitized Solar Cells with an Impressive 45% Fill Factor

“…Recently, different approaches have been exploited to enhance the performances of NiO-based DSSCs. These consist of: (i) synthesis of sensitizers specifically designed for their application in p-DSSCs [20,[23][24][25][26][27][28][29][30][31] and having appropriate photophysical features [32][33][34] to improve JSC; (ii) the engineering of iodine-based electrolyte [35] or its replacement with alternative redox couples [20,[36][37][38][39] to obtain higher VOC; (iii) the amelioration of photocathodes electronic and morphological features [40][41][42][43]. Apart from these, the implementation of an insulating compact layer beneath the photocathode was proven to be an effective approach to reduce the rate of recombination reactions occurring at the FTO-coated glass/photocathode interface, acting as a charge blocking layer [44,45].…”

Conjugated macrocyclic materials with photoactivated optical absorption for the control of energy transmission delivered by pulsed radiations

“…Series of tethered Pcs 34-37 [86][87][88] with OL activity. [31,32,36,59,65]. Table 1 reports some OL characteristics for a series of Ncs dispersed in toluene with linear optical transmission T 0 = 0.7 at the wavelength of analysis of 532 nm for ns laser pulses [32].…”

“…Comparison of the parameters characterizing the OL performance of a series of Ncs from Chart 6 at 532 nm. F lim is the limiting fluence at which NLO transmission equals 0.50 of the linear transmission T 0 , Φ T is the triplet quantum yield, and τ T1 is the lifetime of the highly absorbing triplet excited state according to the scheme of sequential two-photon absorption depicted in Figure 16 [32].…”

Synthesis and Characterization of New Cross‐like Porphyrin–Naphthalocyanine and Porphyrin–Phthalocyanine Pentads

“…This increasingly larger π‐electron system enhances intermolecular π–π interactions, favoring stronger aggregation and lower solubility. Nevertheless, Ncs also feature in several important applications such as, for instance, optical storage and nonlinear optics, especially optical limiting .…”