Nonlinear optical (NLO) materials are the smartest materials of the era, and have the ability to generate new electromagnetic fields with changed frequencies, phases, and other physical properties. Recently, many cutting edge research reports have been focused on NLO materials especially on those which are composed of sp² hybridized carbon nanostructures. As the carbon nanostructures are composed of abundant π-electrons and have significant delocalization, these are potential candidates for modern NLO materials. Generally, sp² hybridized carbon nanostructures can be divided into zero-dimensional fullerenes, one-dimensional nanotubes and two-dimensional graphene nanoribbons and quantum dots etc. These dimensionally different carbon nanomaterials are promising candidates for a wide range of applications in next-generation nanotechnologies. In present feature article, we first briefly explain a theoretical structure–NLO property relationship based on perturbation theory and then elucidate the crucial factors to control the NLO responses. We put together the different random investigations of sp² hybridized carbon nanostructures for NLO application by highlighting the importance of their several structural designs to tune NLO amplitudes. Furthermore, we make a comparative and updated analysis of the NLO properties of dimensionally different sp² hybridized carbon nanomaterials i.e. fullerenes, carbon nanotubes, and graphene nanoribbons and quantum dots. Finally, we make a brief discussion about different aspects and opportunities to use the sp² hybridized carbon nanomaterials as high performance NLO materials of the future. This review is a focused perspective based on different updated quantum chemical investigations about fullerenes, nanotubes and graphene nanoribbons and quantum dots for their possible use in nonlinear optical applications.

Perovskite solar cells (PSCs) are promising photovoltaic (PV) technologies due to their high-power conversion efficiency (PCE) and low fabrication cost. This review article delves into the changing PSC landscape by analyzing the various dimensional diversity, which includes zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) structures, and exploring the potential of mixed-dimensional integrations to improve the stability and performance of these promising PV devices. To fine-tune the properties of perovskite materials, researchers have used cutting-edge methods like passivation strategies, interface engineering, and exact crystal growth control. As a result, significant improvements in open-circuit voltage (V_OC), long-term stability, and PCE have been made. This thorough review also discusses the complex trade-offs involved in each dimensional integration, offering important insights into the complex interplay between material properties, device architecture, and fabrication techniques. Dimensional diversity in PSCs ultimately represents a dynamic path toward advancing the state-of-the-art in PV technology, providing invaluable direction to scientists and engineers attempting to realize the full potential of these next-generation solar cells. In conclusion, this review article offers a thorough analysis of the developments, difficulties, and potential of perovskite-based solar cells. It contributes to the knowledge and development of high-efficiency PSCs that hold great promise in the race for better photovoltaic performance by looking at printing techniques, stability issues, applications, and the special properties of perovskite materials.

Smart fluorescent materials exhibit a controlled fluorescence response to different external stimuli such as pressure, heat, light, pH, etc. Molecular structure and supramolecular assembly via weak intermolecular interactions strongly influence the fluorescence efficiency and colour. In particular, non-planar molecular structures play a significant role in developing solid state fluorescent materials. Triphenylamine (TPA), a typical non-planar propeller molecule with interesting optoelectronic properties, provides an excellent opportunity for developing a variety of molecular fluorescent materials by taking advantage of synthetic feasibility. For example, a donor–acceptor (D–A) aggregation induced emissive (AIE) fluorophore can be developed by integrating an acceptor group into the phenyl unit of a TPA donor. In this review, we focus exclusively on TPA-based smart fluorescent materials that exhibit distinct and reversible fluorescence switching towards different stimuli. Molecular engineering of the TPA fluorophore resulted in the development of different types of stimuli-responsive materials and the conformational flexibility of non-planar phenyl groups often produced polymorphism induced fluorescence tuning. A detailed discussion of the structure–property relationships of TPA derivatives could provide insights for developing new TPA-based smart fluorescent materials with versatile properties.