New carbon based hybrid nanocomposites for photocurrent generation and optoelectronics

During the last decade, nanocomposite materials have spurred large interest, and with the rise of nanotechnology, the development of new nanocomposite materials promoting new properties has taken a step forward. These nanocomposite materials will be the key components for the development of new applications in the field of nanotechnology. The combination of nanoparticles with carbon nanotubes (CNTs) has proven to greatly broaden the area of potential applications, such as gas sensors, solar cells, bio-imaging… Carbon based hybrid nanocomposite combining metal oxide nanoparticles with carbon nanotubes have attracted considerable attention, and it was shown that the presence of carbon nanotubes can influence the growth of these nanomaterials. In fact, carbon based hybrid nanocomposites are an emerging class of nanomaterials that has spurred a lot of interest due to their unique optical properties.

We are investigating potential carbon based hybrid nanocomposites to produce photocurrent under visible light and UV light excitation. Our recent investigations have shown that it is possible to obtain photocurrent production by combining HfO₂ nanoparticles with multi-walled carbon nanotubes. The other nanoparticles coupled with CNT are ZnO and Ag nanoparticles. Both HfO₂ and ZnO when combined with CNT produce a photocurrent however, the origin of these photo-generated charges are quite different as one is a dielectric while the other is a wide band gap semiconductor. In both cases surface defects play an important role is photocurrent generation.

List of relevant publications:

• “ Fabrication and evaluation of figures of merit of ZnO polymer-based hybrid UV photodiodes “
• “Significance of Hydroxyl Groups on the Optical Properties of ZnO Nanoparticles Combined with CNT and PEDOT:PSS“
• “The role of CNT in surface defect passivation and UV emission intensification of ZnO nanoparticles“
• “Assessment of the optical and electrical properties of light emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review“
• “Enhancing the UV emission in ZnO-CNT hybrid nanostructures via the surface plasmon resonance of Ag nanoparticles“
• “Selective photocurrent generation in HfO₂-CNT hybrid nanocomposites under UV and visible photoexcitations“
• “Time evolution of ZnO-CNT photoluminescence under variable ambient and temperature conditions“
• “Influence of the Interface on the Photoluminescence Properties in ZnO Carbon-Based Nanohybrids“
• “Investigations on new carbon-based nanohybrids combining carbon nanotubes, HfO2 and ZnO nanoparticles“
• “A Review of the Synthesis and Photoluminescence Properties of Hybrid ZnO and Carbon Nanomaterials“
• “Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites“
• “One Step Synthesis of Pure Cubic and Monoclinic HfO₂ Nanoparticles: Effects of Temperature and Ambient on the Photoluminescent Properties”
• “Photoluminescent cubic and monoclinic HfO₂ nanoparticles: effects of temperature and ambient”
• “One step synthesis of pure cubic and monoclinic HfO₂ nanoparticles: Correlating the structure to the electronic properties of the two polymorphs”
• “Precursor-Dependent Blue-Green Photoluminescence Emission of ZnO Nanoparticles”

Research project partially funded by the Estonian Centre of Excellence 2015 EQUiTANT (TK134).