CH₃NH₃PbI₃ perovskite:poly(N-vinylcarbazole) blends for broadband optical limiting

Abstract

As one of the most active areas in laser protection, organic/inorganic hybrid functional materials have been expected to play an extremely important role in the field of optical limiting. The optical limiting performance of the CH 3 NH 3 PbI 3 perovskite:poly(N-vinylcarbazole) (weight ratio: 1 : 1) blends (hereafter abbreviated as CP) was experimentally studied in DMF and in a poly(methylmethlacrylate) (PMMA) matrix, respectively, using an open aperture Z-scan method. In contrast to the CP dispersed in DMF, which showed no apparent nonlinear optical (NLO) response at both 532 and 1064 nm, after annealing at 200 C in N 2 for 30 min, a saturable absorption (SA) response was observed in the same DMF dispersion under the excitation of 532 nm laser. At 1064 nm, the annealed sample displayed different NLO responses: SA at the lower pulse energy and reverse saturable absorption (RSA) at the higher pulse energy. Both the 3 wt% and 6 wt% CP-doped PMMA composite films exhibited a typical RSA response, larger nonlinear absorption coefficient and superior optical limiting performance when compared to the same blends in DMF dispersion.In the past decades, signicant research effort has been invested in state-of-the-art optical limiting (OL) materials (e.g. fullerenes, carbon nanotubes, polymer/nanotube composites, porphyrins, phthalocyanines, mixed metal complexes, carbon black suspensions, two dimensional nanosheets, nanowires, nanobers and nanoparticles as well) in an attempt to achieve some measure of protection from laser beams. 1-5 A large number of essential strategies have been employed to control and optimize the OL characteristics of nonlinear optical (NLO) materials for practical laser protection. However, the preparation of novel nonlinear and optically active materials with excellent thermal stability, small limiting threshold value, large laser damage threshold value, ps/ns response time and broadband spectral range, still presents a signicant challenge.Since 2009, organometal halide perovskites (e.g. CH 3 NH 3 -MX 3 (M ¼ Pb, Sn; X ¼ Cl, Br, I), CH 3 NH 3 MBr x X (3Àx) (M ¼ Pb, Sn; X ¼ Cl, I), (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) (xÀ1) Sn x I (3x+1) , CH 3 NH 3 PbCl x -I (3Àx) and others) have attracted signicant attention worldwide, 6-9 especially in organic photovoltaics (including dyesensitized solar cells and other organic solar cells), due to their high electron mobility (66-2300 cm 2 V À1 s À1 ), 10 long exciton diffusion length (100-1000 nm), 11,12 high linear absorption coefficient (1.5 Â 10 4 cm À1 at 550 nm), 13 tunable bandgap (1.17-2.3 eV).8,13,14 However, the NLO and OL performances of these materials have been less studied so far.In this work, we reported for the rst time the NLO and OL properties of the CH 3 NH 3 PBI 3 perovskite:poly(N-vinylcarbazole) (weight ratio: 1 : 1) blends (CP) in DMF and in the PMMA matrix, respectively, by open aperture Z-scan method. The CH 3 NH 3 PbI 3 perovskite was prepared according to the method described in the literature.6 Poly(N-vinylcarbazole) (PVK, M w ¼ 9 Â 10 ...

Broadband femtosecond nonlinear optical properties of CsPbBr_3 perovskite nanocrystals

“…There are few reports in literature on the NLO studies of perovskite colloidal solutions and thin films with different morphologies, input wavelengths and pulse durations [14,18,[19][20][21][22][23][24][25][26][27]28,29]. The NLO coefficients obtained from our studies are on par with those reported recently.…”

“…At room temperature and under low illumination conditions, optical amplification can be achieved in the entire visible spectral range. Inorganic perovskite nanocubes (NCs) exhibit large 2PA cross sections, two orders of magnitude larger than traditional colloidal quantum dots (QDs) [13,14]. In this Letter, we report the NLO properties of all-inorganic cesium lead bromide perovskite (CsPbBr 3 ) nanocrystals of controlled sizes and shapes [NCs and nanorods (NRs)].…”

Defect-Dependent Nonlinear Absorption in the Lead-Free Double-Perovskite Cs2AgBiBr6

“…The optical limiting threshold is 8.1 × 10 –4 J cm –2 (515 nm laser excitation). Figure h and Table S3 in the SI show the comparison between the optical limiting threshold of Cs 2 AgBiBr 6 and other nanomaterials (e.g., typical perovskites, − C60, graphene, SWNT-CPP). The F th value is 1 order of magnitude smaller than the smallest value of perovskite (CsPbBr 3 , 6.2 × 10 –3 J cm –2 ) reported so far.…”

Introducing Optical Nonlinearity in PDMS Using Organic Solvent Swelling

“…In the scope of incorporating optical nonlinearity into PDMS, various approaches have been reported in the literature. Some methodologies involve the integration of nonlinearity through the introduction of chromophores [31,32], plasmonic nanoparticles [33,34], perovskites [35,36], and 2D materials [37,38] into the PDMS. However, a prevalent challenge associated with these techniques is the simultaneous introduction of absorption, particularly noticeable in the case of dyes.…”