Two-dimensional ruddlesden-popper hybrid perovskite quantum dots for optical limiting application

Two-photon absorption in halide perovskites and their applications

“…Recently, Zhao et al fabricated a 2D Ruddelesden–Popper (RP) hybrid perovskite (CH 3 (CH 2 ) 3 NH 3 ) 2 (CH 3 NH 3 ) n −1 Pb n I 3 n +1 ( n = 1, 2, 3, 4) with an average size of 5–7 nm by applying the top-down synthesizing method. 202 By using Z-scan technique, they revealed a TPA coefficient of up to 650 cm GW −1 ; besides, they found that the 2D perovskites feature >50% of the optical limiting at 80 μJ and a maximum of 86% of the optical limiting at 150 μJ, showing great potential in optical limiting applications.…”

Quasi-2D halide perovskite crystals and their optoelectronic applications

“…The synthesis of halide perovskite quantum dots with quantum confinement similar to RP-phase quasi-2D perovskites is mainly implemented via one-pot synthesis 88,89 and top-down synthesis. 90,91 In one-pot synthesis, the precursors dissolved in organic solvent are heated and stirred in round-bottom flasks. Oleic acid and oleylamine are commonly used in this method to confine the size of products.…”

Doubly 1,3-butadiyne-bridged ditwistacene with enhanced ultrafast broadband reverse saturable absorption

“…Dual-mode optical power limiting (OPL) materials, which combine two-photon absorption (TPA) with excited state absorption (ESA) behavior to limit the transmitted intensity of laser pulses to safe power levels, are very promising optical protectors of human eyes and sensitive optical instruments. 1 In contrast with traditional OPL materials, by using nonlinear scattering and large ratios of ESA to ground-state absorption cross section, [2][3][4] the dual-mode materials exhibit enhanced OPL abilities along with low optical losses for low-intensity harmless laser pulses, owing to overlap of ESA with TPA without the contribution of one-photon absorption. Even though a number of materials have been demonstrated to act as dual-mode absorbers, [5][6][7] some disadvantages, such as their small TPA cross sections and weak absorption abilities in the picosecond and femtosecond regimes due to the formation of excited triplet states, hinder the practical applications of these materials in ultrafast broadband OPL.…”