Enhanced Nonlinear Absorption, Refraction, and Optical Limiting Properties of CsPbI<sub>3</sub>/TiO<sub>2</sub> Nanocomposites for Innovative Nonlinear Optical Devices
Muhammad Sohail, Xiong Shen, Intikhab Alam, Zulfiqar Ali, Nimra Razzaq, Qiuyun Ouyang
Abstract
The investigation of nonlinear optical (NLO) properties is crucial for the effective application of CsPbI 3 /TiO 2 nanocomposites in NLO devices. The CsPbI 3 /TiO 2 nanocomposites were synthesized by a hot injection method. Then, the CsPbI 3 /TiO 2 nanocomposites were poured into methyl methacrylate via polymerization to fabricate CsPbI 3 /TiO 2 /PMMA organic glasses (OGs). The crystal structure and size morphology of the CsPbI 3 /TiO 2 nanocomposites were examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The nonlinear absorption (NLA), nonlinear refraction (NLR), and optical limiting (OL) properties of the CsPbI 3 /TiO 2 /PMMA OGs were investigated by using the Z-scan technique, employing a nanosecond pulse laser operating at a wavelength of 532 nm. The CsPbI 3 /PMMA and CsPbI 3 /TiO 2 /PMMA OGs can be transferred from saturable absorption (SA) to reverse saturable absorption (RSA) by varying the incident energy. In addition, the CsPbI 3 /TiO 2 /PMMA OGs exhibit superior NLA, NLR, and OL performances compared to the CsPbI 3 /PMMA OG and other halide-based perovskites. The enhanced nonlinear optical (NLO) properties of CsPbI 3 /TiO 2 /PMMA OGs can be ascribed to the cooperative interaction between CsPbI 3 and TiO 2 . In summary, the results indicate that CsPbI 3 /TiO 2 nanocomposites possess substantial potential for applications in NLO devices such as optical limiters, optical switches, and optical modulators.