Green synthesis of strongly luminescent Si/SiO₂ nanoparticles using Actinidia deliciosa

ABSTRACT

Here we present green synthesis of highly luminescent Si/SiO${}_2$ nanoparticles having an average size of $12.8\pm 0.2\mathrm{nm}$ by one step reduction of 3-aminopropyltriethoxysilane using Actinidia deliciosa as a green reducing agent in water. These water dispersible nanoparticles present an absorption edge at 3.34 eV. An uneven surface oxidation of these nanoparticles appears due to which variable defect sites and their corresponding energy levels are involved in the emission processes. This is why, an excitation dependent emission in these nanoparticles is observed where by decreasing the excitation energy, the emission peak redshifts. The maximum emission quantum yield in these nanoparticles is found to be 27% at 350 nm when the reaction mixture was kept for 5 days. The emission energy and the intensity are found to be dependent on the reaction time due to which their quantum efficiencies also vary.

Keywords:

• Green synthesis
• Si/SiO${}_2$ NPs
• luminescence
• quantum yield
• defects

Acknowledgments

A. Tiwari and A. Tripathi would like to thankfully acknowledge the financial assistance from IUAC, New Delhi. S. Gurung thanks UGC non-NET research fellowship. A. P. Pathak thanks National Academy of Sciences India for award of NASI Sr. Scientist Platinum Jubilee Fellowship. N. Arun thanks NASI for award of Research Associateship in Platinum Jubilee project of APP. We thank UGC-NRC-School of Physics and Center for Nanotechnology (CFN), University of Hyderabad for providing access to necessary experimental facilities. DST-FIST is thankfully acknowledged for the support to Department of Physics, Sikkim University.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

A. Tiwari and A. Tripathi would like to thankfully acknowledge the financial assistance from IUAC, New Delhi. A. P. Pathak thanks National Academy of Sciences India for award of NASI Sr. Scientist Platinum Jubilee Fellowship.

Notes on contributors

Sweta Gurung

Sweta Gurung is a Ph. D. Scholar at Department of Physics, Sikkim University, India and is working under the guidance of Dr. Ajay Tripathi and Dr. Archana Tiwari. She has completed her BSc from Sikkim Government College, Tadong in 2017, and MSc in Physics from Sikkim University in 2019.

Nimmala Arun

Nimmala Arun has received his bachelor degree in engineering from Scient Institute of Technology, Jawahar Nehru Technological University, Hyderabad in 2010. Currently, he is pursuing his PhD in Centre for Advanced Studies in Electronics Science and Technology (CASEST), School of Physics, University of Hyderabad, India and his area of interest includes fabrication and characterization of Resistive Random Access Memory and Electron Beam Lithography.

Ajay Tripathi

Ajay Tripathi graduated with M.Sc. Physics (2001) from Banaras Hindu University, India. He received his Ph.D. from Albert Ludwig Universität, Freiburg im.Breisgau, Germany in 2006. After spending few years at Durham University, England and Quebec University, Quebec as post doctoral researcher, he joined Sikkim University as an Assistant Professor in Physics in 2009. His major research interest is in the field of laser material interactions.

Anand P. Pathak

Anand P. Pathak completed his Ph.D. from Indian Institute of Technology, Kanpur in 1971. He is a Fellow of National Academy of Sciences India (NASI) F N A Sc, IOP (London) F Inst P, C Phys as well as a member of Fellowship and C Phys Panel. He is a former member of UGC Physics Panel (June 94- 2002) and International Committee, “Int.Conf. Atomic Collisions in Solids (ICACS)” AND “Int.Conf. Ion Beam Analysis (IBA)” and Chairman of 20th Int. Conf. Atomic Collisions in Solids ( ICACS20) held in PURI ( INDIA), Jan 2003. He was the director of a workshop on “Ion Beam Studies of NanoMaterials: Synthesis, Modification and Analysis” held at ICTP Trieste Italy, June 2006. He was the chairman at 18th Int. Conf. Ion Beam Analysis (IBA 2007) Hyderabad held in Sept 2007. He is an associate editor of Radiation Effects and Defects in Solids. He was on Editorial Board of Nuclear Instruments and Methods B (2003- 2010). His postdoctoral appointments were in Theoretical Physics Division, AERE., Harewell UK, Commissariat A L'Energie-Atomique, Fontenary-aux-Roses, France. He was a faculty at School of Physics, University of Hyderabad since 1977 where he also served as Dean, school of Physics from Feb 1992- Feb 1996 and then retired as Professor on 31st Dec 2011. He was CSIR Emeritus Scientist till Dec 2016. He served as Guest faculty in IIIT (RGUKT) Basar, Telangana, India and Sikkim University, Gangtok, India. He has served as a Guest Scientist at several institutions worldwide, including Distinguished Research Scientist at CSIRO Australia, Humboldt Fellow in Germany, Chair Professor in Mexico and many more. His research interests are ion solid interactions and ion beam and Laser studies of nano-materials. He has 312 publications (221 International Journals and 69 International and National Refereed Conference Proceedings, 12 Reviews and 10 Books). He has supervised 13 Ph. D. Theses and 10 M. Phil Theses. He is currently a NASI Sr Scientist Platinum Jubilee Fellow since 1st Feb 2020 (& Honorary Professor of Physics since Oct 2017 onwards at University of Hyderabad).

Archana Tiwari

Archana Tiwari did her M.Sc. in Physics (2005) from Banaras Hindu University, India. She did her DPhil. from University of Oxford, UK in 2009 and worked as a postdoctoral researcher at McGill University (in collaboration with University of Saskatchewan), Canada. She was an Assistant Professor in Sikkim University, India from 2009 to 2020 and is now working as an Assistant Professor in Physics at Banaras Hindu University, India. Her research interests include nanomaterials, magnetic and optical sensors and thermoelectric materials.