Research Output per year
Area of academic expertise - outline
I am a Physicist and expert in areas, comprising Material Science, Sensors and Nanotechnology. I have more than 8 years experience in the field of Advanced Semiconductor Materials for the development of Optoelectronic, Photovoltaic, and Sensing Applications.
Research Social Media
Low-power and energy-autonomy are critical features for wider and longer use of wearable systems in emerging applications such as smart-windows, robots, health-monitoring, etc. In fact, this will be needed for any application involving mobility and portability. For example, the future electric cars and drones will have displays that are energy-autonomous or robots that use the light energy to power their limbs actions. While significant effort has been devoted to low-power circuit design, as is evident from ultra-low-power electronics in smartphones today, the longer energy-autonomy is still a challenge. To improve the working life of batteries (i.e. without charging them through mains) a range of energy harvesting schemes have bend explored. Among these, both photovoltaics and piezo-electronics alone have been preliminary demonstrated to generate sufficient energy for low-power consumption wearable systems. However, existing technologies are not suitable for wearable systems as they are generally not flexible and require large areas for power generation. To this end, I believe that my focus on 1) the synthesis of semiconducting nano-materials with different shapes, including nanowires, nanotubes, etc. 2) the investigation of high-performance assembling techniques to integrate nanostructures over large areas and on a wide variety of non-conventional substrates, 3) the development of new low-power sensing devices on flexible substrates, including high-efficiency energy-harvesting devices, and stable energy storing devices based on above nanomaterials, will provide me a solid background to embark on developing energy solutions for future societal needs. Below I have briefly explained a few key parts of my research track.
Fabrication of flexible electronics based on semiconducting nanowires (NWs): In Bendable Electronics and Sensing Technologies (BEST) group at University of Glasgow (UoG), I have explored the synthesis of different semiconducting NWs and their integration on non-conventional large-area substrates by techniques such as contact-printing and dielectrophoresis (DEP) for sensing, photovoltaics and supercapacitor applications. I am familiar with the synthesis of vertically-aligned Si and ZnO NWs by top-down and bottom-up approaches, respectively. In the BEST group, I am developing photovoltaics and electronics based on Si NWs, and ultraviolet (UV) photodetectors, supercapacitors and piezoelectric sensors based on ZnO NWs.
Fabrication of flexible electronics based on graphene: I have a solid background in the transferring of single-layer graphene on flexible and rigid substrates by using hot-lamination and PMMA based methods. I have extensively used Raman spectroscopy to analyze the quality of graphene before and after its transfer to flexible substrates. Moreover, I am proficient with the use of patterning tools such as laser cutting, blade cutting, plasma etching, and lithography to create patterns in graphene which allowed me to fabricate low-power tactile sensors based on single-layer graphene capacitive interdigitated electrodes. These transparent and flexible graphene-based tactile sensors were used as an electronic-skin integrated into a robotic limb to control the grabbing pressure of the robotic fingers.
Growth and characterization of semiconducting nanowires: I completely studied growth mechanisms of III-V and II-VI semiconducting NWs by chemical beam epitaxy and vapor phase transport, respectively, comprising the in-situ and ex-situ analysis of structural, morphological and optoelectronic properties of resulting nanowires. Vertically aligned NWs were used as building blocks in photodetectors at different ranges of the electromagnetic spectrum. This research involved learning of most extended characterization techniques in material science, including XPS, RBS, SEM, AFM, EDAX, XRD, TEM, Raman, IV, CV, Hall, ellipsometry, RHEED, etc.
Micro- and nano-fabrication of electronic and optoelectronic devices: I fully designed, fabricated, and characterized field effect transistors (FETs) based on semiconducting NWs and thin films. I was engaged in an innovative research on the development of optoelectronics/photovoltaics based on earth-abundant materials such as Zn3N2 thin films and single NW photodetectors based on metal oxide compounds such as AZO, ZnO, and CuO. In that research, I fully understood mechanisms governing the charge transport through 1D structures and the way to optimize the response of photodetectors by modifying structural and compositional properties of semiconductors. The research involves learning of standard micro- and nano-fabrication tools in a clean room.
Current research activities
In the University of the West of Scotland, I am a researcher at the Institute of Thin Films, Sensors, and Imaging. In this research group, I am actively participating in multi-disciplinary investigations, comprising the collaboration with national/international institutions, such as Strathclyde University, University of Glasgow, and Universidad Autonoma de Madrid. These research lines aim to explore new advanced materials for the development of self-powered systems and high precision sensors as briefly summarized below:
- Dielectric thin film coatings for low-noise Gravitational Waves detection
- Nanostructured metal oxide thin films deposited by plasma-assisted technology for sensing and energy harvesting applications.
- Fabrication of supercapacitors based on high-dielectric nanostructures assembled by optoelectronic tweezers.
- Fabrication photovoltaic solar cells and photodetectors based on III-V semiconductor compounds with the shape of nanowires.
Current teaching activities and interests
- PHYS09003 Electromagnetism lab classes (12 hours)
SUPA Introductory Data Analysis lectures (6 hours)
PHYS08003 Oscillations Waves and Fields Labs and Tutorials (24 hours)
PHYS09001 Advanced Optics Lectures, Tutorials, and Labs (52 hours)
PHYS11013 Thin Film Devices and Applications Lectures (36 hours)
In 2009, I received a B.S. degree in Physics from the Universidad Autonoma de Madrid (UAM). One year later, I finished a M.S. in Advanced Materials and Nanotechnology at the Department of Applied Physics (UAM). In 2010, I joined the research group of Electronics and Semiconductors (ELySE) at UAM, and one year later I became a Research Fellow (Spanish FPI MINECO Fellowship) at ELySE. Between 2012 and 2013, I carried out two visiting researches for three months at The University of Alabama under the supervision of Prof. Patrick Kung (characterization of GaAs nanowires by TEM and Raman spectroscopy), and The Walter Schottky Institut (fabrication of functionalized ZnO nanowires based liquid gate field-effect transistors) under the supervision of Dr. Jose Antonio Garrido. In July of 2015, I obtained a Ph.D in Physics (summa "cum laude") entitled "Contribution to the Development of Electronic Devices Based on Zn3N2 Thin Films, and ZnO and GaAs Nanowires." In October of 2015, I joined Bendable Electronics and Sensing Technologies (BEST) group at the University of Glasgow (led by Prof. Ravinder Dahiya), as a Postdoctoral Research Assistant. During this period, I investigated contract-printing of semiconductor nanowires for flexible electronics and tactile sensitive electronic-skin (e-skin) for robotics. In December of 2017, I joined Micromanipulation Research Group at the University of Glasgow (led by Dr. Steven Neale) to investigate the assembly of high dielectric nanostructures by optoelectronic tweezers for energy storage applications such as supercapacitors.
In August 2018, I became a Lecturer in Physics at the University of the West of Scotland and joined to the Institute of Thin Films, Sensors, and Imaging (TFSI) led by Prof. Desmond Gibson. At this time, I became an Affiliate Lecturer at the University of Glasgow, working in collaboration with Micromanipulation Research Group.
Since 2011, I have published above 30 articles – 18 as the first author – in peer-reviewed Journal Articles and International Conference Proceedings, 1 Book Chapter and 1 Intellectual Property (see Publications Tab). I have actively participated in multidisciplinary research projects, including the fabrication and characterization of sensors, biosensors and thin film transistors (TFTs) based on earth-abundant materials such as Zn3N2, IR/VIS/UV photodetectors based on zinc oxide (ZnO) and gallium arsenide (GaAs) nanowires (NWs), and III-V multi-band photovoltaic cells. Above applications were fabricated mainly in a radio-frequency magnetron sputtering and chemical beam epitaxy (CBE) system.
Affiliate Lecturer, University of Glasgow1 Aug 2018 → …
Postdoctoral Research Assistant, University of Glasgow6 Dec 2017 → 31 May 2018
Postdoctoral Research Assistant, University of Glasgow1 Sep 2015 → 5 Dec 2017
Postdoctoral Research Assistant, Universidad Autonoma de Madrid - Applied Physics Department1 May 2015 → 30 Aug 2015
- QC Physics
- Materials science
- Thin Films
- Plasma Deposition
- Optoelectronic Tweezers
- Energy Harvesting
- Energy Storage
- Electronic Skin
- Flexible Electronics
- Self-powered Systems
A novel growth method to improve the quality of GaAs nanowires grown by Ga-assisted chemical beam epitaxyGarcía Núñez, C., Brana, A. F., Lopez, N. & Garcia, B. J. 8 May 2018 In : Nano Letters. 18, 6, p. 3608-3615 8 p.
Research output: Contribution to journal › Article
Research output: Contribution to conference › Poster
Research output: Contribution to conference › Paper
Research output: Contribution to conference › Poster
Heterogeneous integration of contact-printed semiconductor nanowires for high-performance devices on large areasGarcía Núñez, C., Liu, F., Navaraj, W. T., Christou, A., Shakthivel, D. & Dahiya, R. 13 Aug 2018 In : Microsystems & Nanoengineering. 4, 15 p., 22
Research output: Contribution to journal › Article
Activities per year