Nanoscience Research Group 

Our researchers conduct research at the frontiers of current knowledge on a wide range of advanced materials, helping to discover new electronic and photonic applications

About

Aston’s Nanoscience Research Group (NRG) conducts cutting-edge research on materials with the potential for a range of real-world applications and benefits. 

Materials of particular interest include: 

  • Carbon nanotubes 

  • Graphene and 2D materials 

  • Nano-diamond and Zinc oxide  

  • Synthetic fluorescence and laser dyes 

  • Natural pigments and polymer composites.

Realising the full potential of such materials is a challenge, yet our ability to develop both hybrid and composite materials as well as conduct surface functionalisation puts us at the forefront of our field. 

Modifying materials in this way allows them to be integrated them into new optical platforms, with the prospect of dramatic improvements across a range of instruments as a result. These can include ultra-short pulse lasers, biological and gas sensors, and much more.

Our Facilities

Our state-of-the-art wet chemistry nanomaterial processing facilities include: 

  • Ultrasonic processor and shear force mixer 

  • Benchtop centrifuges and ultracentrifuge 

  • Autodrop Ink-jet printing system 

  • Density gradient station 

  • Polymer nano-composite and nano-ink fabrication 

  • Filtration systems.

Our imaging and advanced material optical characterisation capacities include: 

  • Absorption/transmission spectroscopy 

  • Photoluminescence excitation Emission spectroscopy 

  • Scanning electron microscopy 

  • Holotomographic microscopy.

Our knowledge base at Aston spans multiple disciplines, and by working together, and with funding from EU Horizon 2020, RCUK, The Royal Society, The royal Academy of Engineering etc, we aim to be at the forefront of the development and utilisation of functional nanomaterials.  

Our Projects

Development of carbon nanomaterials-based saturable absorbers and property analysis

Composites of single-walled carbon nanotubes (SWNTs) and water-soluble polymers (WSP) are the focus of significant worldwide research due to a number of applications in biotechnology and photonics, particularly for ultrashort pulse generation. Despite the unique possibility of constructing non-linear optical SWNT-WSP composites with controlled optical properties, their thermal degradation threshold and limit of operational power remain unexplored. In this study, we reveal the nature of the SWNT polyvinyl alcohol (PVA) film thermal degradation and evaluate the modification of the composite properties under continuous high-power ultrashort pulse laser operation. 

M. Chernysheva, M. Al Araimi, G.A. Rance, B. Shi, S. Saied, J.L. Sullivan, N. Marsh, A. Rozhin “Revealing the nature of morphological changes in carbon nanotube-polymer saturable absorber under high-power laser irradiation”, Scientific Reports, 8, 7491 (2018). 

Mode-locked fibre lasers with carbon nanomaterials saturable absorbers

We systematically study the impact of average cavity dispersion and pulse spectral bandwidth on harmonic mode locking in the long-wavelength band from an Er-doped fiber laser using carbon nanotubes polyvinyl alcohol (CNTs-PVA) film mode locker. By carrying out pulse energy management through optimizing the average cavity dispersion and optical spectral bandwidth, 2.08 GHz repetition rate corresponding to the 201st harmonic with 36.5 dB side mode suppression ratio was realized under 205 mW pump power at 1597.53 nm. The laser source featuring high repetition rate in L-band operation is very promising for applications in optical communication systems. 

Q Huang, C Zhao, T Wang, M Al Araimi, A Rozhin, C Mou “Influence of Average Cavity Dispersion and Spectral Bandwidth on Passively Harmonic Mode Locked L-Band Er-Doped Fiber Laser” IEEE Journal of Selected Topics in Quantum Electronics, 25, 0900408, (2019). 

Sensing of ammonia by ultrasonically treated carbon nanotube network

The exceptional properties of carbon nanotubes (CNTs) have resulted in the development of various nano-scaled devices, particularly CNT-based sensors of ammonia (NH3) with outstanding performance. Our recent research in collaboration with the Tokai University (Japan) focused on CNT-based network sensors of NH3 has allowed to develop a better understanding of their gas detection behaviour and enhanced sensing response. Our studies showed improved sensing performance for single-walled CNTs of (6,5) chirality ultrasonically treated at high power and then forming bundled nanotube network upon thermal annealing. The sensitivity is attributed to the ultrasonically induced defects formed on the nanotube surface. Two chemiresistive sensing pathways were observed for such networks resulting in increased and decreased resistance in the the presence of different ammonia concentrations from 102 to 104 ppm. This multidirectional chemiresistive response was comprehensively explained via various phenomena, such as partial and full neutralization of p-type conductivity of CNTs, change of the Schottky barrier, and dipoles at the interface between nanotubes and gold electrodes. The proposed sensing mechanisms are believed to provide strong support for further development of ammonia sensors with optimized performance 

P.M. Lutsyk, P. Shankar, A.G. Rozhin, S.A. Kulinich, Surface sensitivity of ultrasonically treated carbon nanotube network towards ammonia, Surfaces and Interfaces 17, 100363 (2019). 

Photodetectors Based on 2D Hafnium Selenosulfide Nanosheets (Collaboration)

In recent years, 2D transition‐metal dichalcogenides have attracted great research interest due to their multiple degrees of freedom in tuning their physical properties via band engineering and dimensionality adjustment. The fellow propose to use 2D hafnium selenosulfide HfSSe (HSS) single crystal for high performance photodetectors. 

High quality 2D hafnium selenosulfide HfSSe (HSS) single crystals grown by chemical vapour transport exhibits excellent phototransistor performance from the visible to the near‐infrared with outstanding stability.  A large photoresponsivity (≈6.4 × 104 A W−1 at 488 nm)  with high specific detectivity (≈1014 Jones) were explored from the device fabricated with exfoliated HSS single‐crystal of nano-metric thickness on a rigid Si/SiO2 substrate. In addition, the device performance extended to explore flexible photodetector As compared to other existed 2D chalcogenides, the CVT grown HSS exhibit better device performance in terms of photoresponsivity. The fellow recommends HSS single crystal for future wearable electronics and optoelectronic circuits. 

Ulaganathan, R. K.; Sankar, R.; Lin, C. –Y.; Raghavan, C. M.; Tang, K.; Chou, F. –C. High‐performance flexible broadband photodetectors based on 2D hafnium selenosulfide nanosheets. Adv. Electron. Mater. 6, 1900794 (2019). 

People 

Academic Staff
  • Dr. Alex Rozhin, Reader in Nanotechnology, Visiting Professor (111 collaborative project), Key Laboratory of Specialty Fiber Optics and Optical Access Netwokrs, Shanghai University, China 
     
  • Dr. Petro Lutsyk,  Lecturer in Electronic Engineering and Systems 
Research Fellows
  • Dr. Raghavan Chinnambedu-Murugesan, Marie Sklodowska- Curie Individual Fellow 
PhD Students & Research Assistants
  • MonPlas ESR- PhD student (TBA) 
     
  • EAS PhD Student (TBA)
  • Mr. Mohammed Choudhury

Academic & Industrial Visitors
  • Prof Chengbo Mou,  
     
  • Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, Shanghai, China 
     
  • Dr Mohammed Al Araimi 
     
  • Engineering Department, Higher College of Technology, Al-Khuwair, Sultanate of Oman.