A Theoretical Perspective on Strategies for Modeling High Performance Nonlinear Optical Materials

Abstract

Nonlinear optical (NLO) materials have spanned a large area of science and technology owning to their potential applications in optoelectronics. The invention of the first Ruby laser has sparked a fresh interest in the area of nonlinear optics. The computational designing and experimental synthesis of organic and inorganic NLO materials with higher order nonlinearities come into vogue in the field of materials science. To date, several strategies including metal ligand framework, push pull mechanism, diradical character, and so on have been devised to enhance the NLO response of materials. In addition, introduction of diffuse excess electrons is an efficient approach to design noncentrosymmetric materials for nonlinear optics. The current review highlights a systematic array of different computational studies (covering the last decade of intensive research work) for the theoretical designing of NLO materials. In the present review, theoretical designing from the simplest NLO material to the complex alkali, alkaline earth, transition, and superalkali doped nanomaterials is summarized. The emergence of excess electrons strategy has played a pivotal role in enhancing the NLO properties especially hyperpolarizabilities. We expect that this review will provide a better understanding of the NLO responses of nanoclusters, paving the way for the advancement of hi-tech NLO materials to meet the real challenges in optoelectronics.

Geometrical Stability and Nonlinear Optical Properties of Crystallogen and Pnictogen Fullerene Analogues

“…Before concluding, we compare our obtained NLO properties (second hyperpolarizability) to those of the most promising materials for NLO applications. According to Bano et al, 68 there are some strategies for the enhancement of the NLO response, including electron donor to acceptor push−pull mechanisms, 69 designing octupolar molecules, introducing diffuse excess electrons, 70 using multidecker sandwich clusters, applying bond length alteration theory, 71 designing metal organic frameworks (MOFs), etc. Among all considered systems within this review, since each strategy comprises a group of complexes, our model of Bi 60 shows an exceptionally large NLO response of 13.5 × 10 5 au (22 500 au/ atom).…”

Mixed superalkalis are a better choice than pure superalkalis for B12N12 nanocages to design high-performance nonlinear optical materials

“…48 Other inorganic nanocages doped with superalkalis show enhanced NLO responses as well. 49,50 O 12 shows the highest NLO response of 3.94 × 10 5 au. 52 Some superalkalis show an ionization potential of 3.0 eV, which is much smaller than that of cesium metal (3.89 eV).…”

“…48 Other inorganic nanocages doped with superalkalis show enhanced NLO responses as well. 49,50 Ullah et al designed Li 2 F, Li 3 O, and Li 4 N superalkali doped B 12 P 12 nanocages for this purpose, with Li 2 F@B 12 P 12 having the highest NLO response of 3.48 × 10 5 au. 51 Theoretical investigations into the Li 3 O, Na 3 O, and K 3 O superalkali doping of Zn 12 O 12 nanocage revealed that K 3 O@Zn 12 O 12 shows the highest NLO response of 3.94 × 10 5 au.…”

Enhancement in Nonlinear Optical Response of Oligothiophenes by Induction of Polarons

“…According to the literature ( vide supra ), numerous strategies have been proposed to design and synthesize highly efficient nonlinear optical materials such as doping, the push–pull mechanism, extensive π-electronic conjugation, and intramolecular charge transfer . Conducting polymers have extensively been studied theoretically by us and others regarding doping, sensors, and composite formation with other nanomaterials and for resolving structural ambiguities. − It has been observed that polaronic states of conducting polymers have absorption spectra in red to near-infrared (NIR) regions.…”