Laser fabrication of metallic nanostructures emerged as a fascinating approach and these nanostructures received huge interest due to obtaining precise composition, uniform nanosize and shape for their next generation applications such as surface enhanced Raman spectral probing, biosensors, photothermal conversion, water desalination, photovoltaic, photodetector, antireflection, thermal actuators, plasmonic devices, super capacitors and piezoelectric/triboelectric nanogenerators for harvesting mechanical energy. Moreover, due to excellent dimensional and morphological control of the laser-fabricated nanostructures, various metal (such as silver (Ag), gold (Au), cupper (Cu)) nanomaterials with uniform size and shape and their nanocomposites can be obtained by tuning of controlled selection of the solvent, chemical precursors, photoinduced heating and melting and variation of different lasing and environmental parameters, which can lead to diverse morphological and physicochemical properties and therefore highly controlled mechanical, electronic and optical properties. Recently, piezoelectric and triboelectric nanogenerators have attracted tremendous interest due to their advance technological applications such as harvesting mechanical energies from living environment including irregular and low-frequency wave energy such as eye blinking, heart beat, rain drop, walking, wind flow etc and for designing self-powered nanosensors and powering small scale portable devices such as IoT (Internet of Things) based health monitoring, pH Sensors, wireless nanosensor, gas sensor, heavy metal detection, photo-detector, tactile sensor and self-powered sensors for data collection, implantable biological devices and self-powered water splitting system. However, performance of the nanogenerators highly depends on various factors including the surface morphology, work function, metal-polymer interface piezoelectric charge coefficient, electrode selection and metal-semiconductor interface. Therefore, improving the nanogenerator performance such as output voltage/current was always very challenging in inorganic and organic nanostructures. Recently, graphene, graphene quantum dots, carbon nanotubes (CNT) and semiconductors have been used as reinforcing materials to enhance the piezoelectric and triboelectric characteristics of the active materials. In addition, 2D layered-materials including graphene, layered double hydroxides, transition metal dichalcogenides (TMDCs), transition metal dioxides (TMDOs) have also become hot materials of choice to design and develop the nanoelectronics sensors due to their superior property such as high stability at room temperature, high mechanical-strength, high chemical stability and their outstanding physical and chemical property. However, synthesis of the controlled metal nanostructures, their composite nanostructures and their dispersion in 2D nanostructures such as MoS2, WS2 and ZnO nanosheets are very challenging due to their highly hydrophobic tending to self-entangle in solvents.
In the proposed project, highly controlled metal nanostructures such as Ag and Au nanoparticles/ nanowires will be fabricated by the laser-induced synthesis route by optimising the growth laser parameters. The 2D nanostructures such as pristine MoS2, WS2 and borophene will be decorated with the laser-produced silver and gold nanoparticles. Flexible nanogenerators will be constructed on flexible ITO/PET substrate under polymer matrix, specially with the PDMS polymer. The synthesized metallic nanostructures and their nanocomposites will be investigated through Raman, HR-TEM, FE-SEM, XRD and FT-IR method. In next, laser induced growth of the Ag and Au nanowires grown on substrate will be used as top electrode for device fabrication. Laser-produced conducting nanostructures and 2D based flexible piezoelectric/triboelectric nanogenerator will be fabricated to harvest mechanical energies under controlled condition. The effect of the laser -produced nanostructures on the performance of the device will be measured under different condition. The flexible piezoelectric nanogenerator will be fabricated and their performance will be analysed. The device performance will be measured under several condition and results will be published in reputed journal and joint proposal (RSF-DST in 2025 or 2026) will be submitted.