Our research group is focuses on the design, synthesis, and integration of advanced functional materials to engineer and control light–matter interactions for next-generation optoelectronic and energy systems. We operate at the interface of nanomaterials science, device physics, and light-driven chemical processes, with a strong emphasis on translational research that enables patented technologies and deployable prototypes.

We specialize in low-dimensional material systems, spanning two-dimensional nanosheets to zero-dimensional quantum-confined structures, enabling precise control over electronic, optical, and ionic transport phenomena. Our work integrates materials innovation, device engineering, and system-level functionality, positioning the group at the forefront of emerging optoelectronic, ionotronic and, neuromorphic technologies.

Current Research Thrusts

1. Next-generation self-powered and high-temperature broadband photodetectors

We are developing self-powered, broadband (UV–Vis–NIR) photodetectors with enhanced sensitivity, zero-bias operation, and negligible dark current. These devices are engineered on flexible, lightweight, and unconventional substrates (e.g., paper, polymer platforms), enabling low-cost, portable, and environmentally sustainable sensing technologies.

A major focus is on thermally resilient photodetection, where our devices demonstrate reliable operation from room temperature to ~500 °C, significantly surpassing the limitations of conventional silicon and InGaAs-based technologies. These advances are supported by recent innovations in hybrid p–n heterojunction architectures, and are further strengthened by externally funded research initiatives (ANRF-ARG ~ Rs. 63.96 lakhs, 2026-2029).

2. Bio-inspired optoelectronics for artificial vision

Our group is advancing retinomorphic and event-driven photodetectors that emulate the adaptive response of the human visual system. These systems exhibit intensity-dependent signal processing and zero-bias operation, enabling efficient, low-power, energy-efficient artificial vision platforms.

In parallel, we are pioneering opto-ionotronic synaptic devices, integrating optoelectronics with ionic transport and microfluidic architectures. These systems enable continuous-time signal processing, hardware-level computing, and neuromorphic functionality, representing a significant step toward next-generation intelligent, in-sensor image processing.

3. Optofluidics and ionotronic device architectures

We explore optofluidic platforms coupled with solid-state ionic transport mechanisms to realize adaptive, reconfigurable, and biologically inspired device architectures. Our recent work demonstrates continuous-time differentiation and integration at the hardware level, opening new directions towards in-sensor analog computing and unconventional information processing.

4. Light-driven chemical transformations and photothermal systems

Our research extends beyond photodetection into light-activated and photothermal chemical processes, where we design functional nanomaterials to drive industrially relevant reactions under light irradiation. These include:

• Photothermal catalytic systems for efficient chemical conversion

• Light-induced pathways for sustainable chemical transformations

• Materials for energy-efficient reaction engineering

These efforts are complemented by patented approaches for light-driven polymer upcycling and catalytic systems, highlighting the strong translational impact.

5. Fundamental materials science of multivalent and low-dimensional systems

We investigate the structure–property relationships in multivalent and low-dimensional materials, particularly focusing on elemental chalcogens and transition-metal carbides/borides. Our work elucidates:

• Dimensionality-driven phase transformations (3D → 2D systems)

• Multivalency-induced structural evolution

• Correlation between structure and optoelectronic/photothermal properties

This fundamental understanding underpins the development of next-generation functional materials for devices and catalysis.

Previous Research Contributions

Our earlier work has established strong foundations in nanomaterials synthesis, photonics, and energy systems, including:

• Carbon-based nanostructures (carbon dots, CNTs, graphene) for optoelectronics and energy harvesting

• White-light emitting LEDs based on remote phosphor technology

• Boron-based nanomaterials derived from transition-metal diborides

• Carbide nanosheets and quantum dots for catalytic and photonic applications

• Heavy metal-free phosphorescent materials and devices

• Passive photonic sensors for detection of hazardous chemicals and explosives

• Multifunctional silicon nanostructures for antireflection, SERS, and photodetection

We have also demonstrated high-efficiency light-driven polymer-to-monomer conversion technologies, along with multiple innovations translated into granted patents and scalable device architectures. 

Our research is characterized by a strong synergy between fundamental science and technological innovation, with outputs spanning high-impact publications, patents, and competitve externally funding. We aim to develop scalable, sustainable, and intelligent material-device platforms addressing challenges in energy, sensing, artificial vision systems and next-generation computing.

Doctoral students (research area)

- Ms. Varsha Sharma (Event-responsive, retinomorphic sensors, artificial ionotronic synaptic devices)

- Ms. Henna Sherin P. (Higher-operating-temperature Near-IR photodetectors; Self-powered photodetectors for UV-vis-NIR detection - INSPIRE funding)  

- Ms. Anupama M. (Development of materials for efficient, light-triggered, industrially-relevant chemical reactions, Thesis submitted)

- Ms. Gana K.G. 

Completed doctoral research

- Dr. Swathi V. M. (Multivalency-induced structural variations and related opto-electronic properties of elemental chalcogen nanostructures)

- Dr. Saju K. John (Optoelectronic properties of boron-based nanostructures derived from metal diborides)

- Dr. Nishaina Sahadev (Energy harvesting applications of low-dimensional carbon-based system)

- Dr. Julin Joseph (Luminescent carbon dots for chemical sensing, phosphorescence and white-light emitting device applications)

- Dr. A. Simimol (Defect-induced electrodeposited ZnO nanostructures: optical, magnetic and electrical properties)

- Dr. Prajith K. (Multifunctional Silicon nanopillars for Antireflection, Surface Enhanced Raman Spectroscopy and photodetector applications)

List of patents: Published (2026)

- Aji A. Anappara, Varsha Sharma, Henna Sherin P., Anupama K. S., Desouza Ivan Jemi, Allen Samuel Stephen, A scalable solid-state ionic transport device for continuous-time hardware-level differentiation and integration, Appl. No.: 202641033335 (Published on 27/03/2026) 

List of patents: Published/Granted (2024-'25)

- Aji A. Anappara, Henna Sherin P, High-temperature broadband photodetector based on a self-powered hybrid p-n junction, Appl. No.: 202541104335 A (Published on 28/11/2025)

- Aji A. Anappara, Varsha Sharma, Artificial opto-ionotronic synaptic device, Appl. No.: 202541019070 A (Published on 21/03/2025)

- Aji A. Anappara, Varsha Sharma, A dark-current free self-powered photodetector based on Vanadium carbide (VC) - Silver (Ag) heterostructures, Appl. No.: 202443062912 A (Published on 28/03/2025)

- Aji A. Anappara, Varsha Sharma, An edible event-responsive photodetector for light intensity detection and method of operation thereof, Patent No.:565859 (Granted on 30/04/2025)

- Aji A. Anappara, Anupama M., A method of the fabrication of pristine Vanadium monocarbide quantum dots for the reduction of nitrobenzene, Patent No.: 565289 (Granted on 17/04/2025)

- Aji A. Anappara, Haribabu Krishnan, Anupama M., Juliana John, Karnapa Ajit, Fabrication method of Vanadium monocarbide nanosheets as efficient anode catalysts for single-chamber microbial fuel cells, Patent No.: 560607 (Granted on 19/02/2025)

-  Aji A. Anappara, Varsha Sharma, A zero-bias retinomorphic photodetector on a paper-based substrate and a method of fabricating the same, Patent No.: 557484 (Granted on 06/01/2025)

- Aji A. Anappara, Varsha Sharma, A dark-current free and carrier-diffusion based self-powered photodetector and method of operating the same, Patent No.: 532661 (Granted on 12/04/2024)

- Aji A. Anappara, Varsha Sharma, A charge carrier-diffusion based self-powered photodetector based on Hafnium diboride/Silver heterostructures, Patent No.: 529570 (Granted on 21/03/2024)

- Aji A. Anappara, Varsha Sharma, A Niobium diselenide based self-powered photodetector, Patent No.: 551014 (Granted on 25/09/2024)

- Aji A. Anappara, Varsha Sharma, Fabrication of a self-powered photodetector based on thermo-diffusion effect in ionic liquids, Patent No.: 541052 (Granted on 06/06/2024)

- Aji A. Anappara, Anupama M., A method of synthesizing oxalate-functionalized Niobium monocarbide nanosheets for efficient photothermal conversion and light-triggered chemical reactions, Patent No.: 547506 (Granted on 12/08/2024)

- Aji A. Anappara, Parameswaran P., Saju K. John, A method for the visible light-induced selective degradation of poly(propylene carbonate) to its monomer propylene carbonate, Patent No.: 515351 (Granted on 26/02/2024)

Publications in peer-reviewed journals (reverse chronological order)

41. V. M. Swathi, and, Aji A Anappara, Ultraviolet emission from 2D tellurium nanosheets synthesised using diverse exfoliation techniques, Applied Physics A, 131, 844 (2025)

40. Varsha Sharma and, Aji A Anappara, Cellulose fiber tortuosity as a bio-inspired design strategy for light-driven, self-powered ionotronic synapses, ACS Applied Materials & Interfaces, 17, 48, 65781–65792 (2025)

39. V. M. Swathi, Anjana E Sudheer, G. Tejaswini, Muthu Vallinayagam, T. Pandiyarajan, D. Murali, Matthias Zschornak and, Aji A Anappara, Deciphering the crystal structure evolution from 3D non-van der Waals solids to 2D nanosheets, Journal of Materials Chemistry C, 13, 22278 - 22286 (2025)

38. M Anupama, Anjana Edathirinji Sudheer, Murali Devaraj, Pandiyarajan Thangaraj, Assa Aravindh Sasikala Devi, Aji A Anappara, Unveiling the potential photothermal activity of vanadium carbide for driving chemical reactions, Langmuir, 41, 28, 18544–18553 (2025)

37. M. Anupama, Reeja Gopalakrishnan Nair, Aji A. Anappara, Selective etching of Aluminium towards the synthesis of AlB₂ derived aqueous dispersion of luminescent boron-based nanosheets, Appl. Phys. A, 131, 39 (2025)

36. V.M. Swathi, K. Arjun, Anju Rajan, Raghu Chathanathodi, Karthikeyan Balasubramanian, Aji A. Anappara, Multivalency-induced structural variations of 2D selenium nanosheets: facile solution-phase synthesis and optical properties, PhysChemChemPhys, 26,33, 22112-22121 (2024)

35. Julin Joseph, Aji A. Anappara, Comparative photoluminescence study of nitrogen doped carbon dots co-doped with boron and sulphur, Luminescence, 37, 9,1481 (2022)

34. Akhila A.K., Suresh Babu A.R., Aji A. Anappara, Renuka N.K., Specific ultralow level chemorecognition using graphene-fluorophore supramolecular assembly: Fine-tuning the fluorophore framework, Spectrochimica Acta Part A, 266, 120408 (2022)

33. Vidya T., Anupama M. Sajan M., Julin Joseph, Aji A. Anappara, Multi-functional carbon dots for visual detection of picric acid and white-light emission, Materials Research Bullettin, 138, 111223 (2021)

32. Anci V. A., Thasleena Panakkal, Aji A. Anappara, Renuka N. K., Acetic acid derived carbon dots as efficient pH and bio-molecule sensor, International Journal of Environmental Analytical Chemistry, 101, 506-512 (2021)

31. Nishaina Sahadev, Aji A. Anappara, Photo-to-thermal conversion: effective utilization of futile solid-state carbon quantum dots (CQDs) for energy haevsting applications, New Journal of Chemistry, 44, 25, 10662-10670 (2020)

30. Saju K. John, Aji A. Anappara, Facile synthesis of aqueous-dispersed luminescent nanosheets from non-layered lanthanum hexaboride, RSC Advances, 10, 31788-31789 (2020)

29. Saju K. John, Aji A. Anappara, Aqueous dispersion of highly luminescent boron-rich nanosheets by the exfoliation of polycrystalline titanium diboride, New Journal of Chemistry, 43, 9953-9960 (2019)

28. Nishaina Sahadev, Aji A. Anappara, Photothermal effect in solid-state MWCNT: Possible signatures of thermal anisotropy, Journal of Applied Physics, 124, 145104 (2018)

27. Prajith Karadan, Shantanu Aggarwal, Aji A. Anappara, Chandrabhas Narayana, Harish C. Barshilia, Tailored periodic Si nanopillar based architectures as highly sensitive universal SERS biosensing platform, Sensors and Actuators B: Chemical, 254, 264-271 (2018)

26. Julin Joseph, Aji A. Anappara, Ellagic acid-functionalized fluorescent carbon dots for ultrasensitive and selective detection of mercuric ions via quenching, Journal of Luminescence, 192, 761-766 (2017)

25. Nishaina Sahadev, Aji A. Anappara, Enhanced photothermal effect in reduced graphene oxide in the solid-state, Journal of Applied Physics, 122, 185103 (2017)

24. Prajith Karadan, Santhanu Parida, Arvind Kumar, Aji A. Anappara, Sandip Dhara, Harish C. Barshilia, Charge transport studies on Si nanopillars for photodetectors fabricated using vapor phase metal-assisted chemical etching, Applied Physics A, 123, 681 (2017)

23. Saju K. John, Daughty K. John, N. Bijoy, Raghu Chathanathodi, Aji A. Anappara, Magnesium diboride: An effective light-to-heat conversion material in the solid-state, Applied Physics Letters, 111, 033901 (2017)

22. Julin Joseph and Aji A. Anappara, Long lifetime room-temperature phosphorescence of carbon dots in aluminum sulfate, ChemistrySelect, 2, 4058-4062 (2017)

21. Julin Joseph and Aji A. Anappara, Cool white, persistent room-temperature phosphorescence in carbon dots embedded in a silica gel matrix, PhysChemChemPhys, 19, 15137-15144 (2017)

20. Julin Joseph and Aji A. Anappara, White-light emitting carbon dots prepared by the electrochemical exfoliation of graphite, ChemPhysChem., 18, 292-298 (2017)

19. A. Simimol, Aji A. Anappara and Harish C. Barshilia, Influence of defects on electrical properties of electrodeposited co-doped ZnO nanocoatings, Materials Research Express, 4, 015001 (2017)

18. Julin Joseph, Aji A. Anappara, Microwave-assisted hydrothermal synthesis of UV-emitting carbon dots from tannic acid, New Journal of Chemistry, 40, 8110-8117 (2016)

17. Prajith Karadan, Siju John, Aji A. Anappara, Chandrabhas Narayana, Harish C. Barshilia, Evolution mechanism of mesoporous silicon nanopillars grown by metal-assisted chemical etching and nanosphere lithography: correlation of Raman spectra and red photoluminescence, Applied Physics A, 669, 122-132 (2016)

16. Julin Joseph, Aji A. Anappara, White light emission of carbon dots by creating different emissive traps, Journal of Luminescence, 178, 128-133 (2016)

15. Prajith Karadan, Aji A. Anappara, V.H.S. Moorthy, Chandrabhas Narayana, and Harish C. Barshilia, Improved broadband and omnidirectional light absorption in silicon nanopillars achieved through gradient mesoporosity induced leaky waveguide modulation, RSC Advances,  6, 109157-109167 (2016)

14. A. Simimol, Aji A. Anappara, S. Greulich-Weber, Prasantha Chowdhury and Harish C. Barshilia, Enhanced room temperature ferromagnetism in electodeposited co-doped ZnO nanostructured thin film by controlling the oxygen vacancy defects, Journal of Applied Physics, 117, 214310 (2015)

13. A. Simimol, N. T. Manikandanath, Aji A. Anappara, Prasantha Chowdhury, and Harish C. Barshilia, Tuning of deep level emission in highly oriented electrodeposited ZnO nanorods by post growth annealing treatments, Journal Applied Physics, 116, 074309 (2014)

12. R. Huber, Aji A. Anappara, G. Gunter, A. Sell, S. De Liberato, C. Ciuti, G. Biasiol, L. Sorba, A. Tredicucci, and A. Leitenstrorfer, Switching ultrastrong light-matter coupling on a subcycle scale, Journal Applied Physics, 109, 102418 (2011)

11. Aji A. Anappara, Simone De Liberato, Alessandro Tredicucci, Cristiano Ciuti, Giorgio Biasiol, Lucia Sorba, and Fabio Beltram, Signatures of ultrastrong light-matter coupling regime, Phys. Rev. B 79, 201303(R) (2009)

10. G. Gunter, Aji A. Anappara, J. Hees, A. Sell, G. Biasiol, L. Sorba, S. De Liberato, C. Ciuti, A. Tredicucci, A. Leitenstrorfer and R. Huber, Sub-cycle switch-on of ultrastrong light-matter interaction, Nature, 458, 178-181 (2009)

9. Sajan D. George, Aji A. Anappara, P.R.S. Warrier, K.G.K. Warrier, P. Radhakrishnan, V.P.N. Namboori, Photoacoustic thermal characterization of Al2O3-Ag ceramic nanocomposites, Materials Chemistry and Physics, 111, 38-41 (2008)

8.  Aji A. Anappara, Alessandro Tredicucci, Fabio Beltram, Lucia Sorba, Giorgio Biasiol, Tailoring light-matter interaction in intersubband microcavities, Physica E; Low-dimensional Systems and Nanostructures, 40, 1906-1908 (2008)

7.  Aji A. Anappara, Alessandro Tredicucci, Fabio Beltram, Lucia Sorba, Giorgio Biasiol, Cavity polaritons from excited subband transitions, Applied Physics Letters, 91, 231118-231122 (2007)

6.  Aji A. Anappara, Alessandro Tredicucci, Fabio Beltram, Giorgio Biasiol, Lucia Sorba, Controlling polariton coupling in intersubband microcavities, Superlattices and Microstructures, 41, 308-312 (2007)

5.  Aji A. Anappara, David Barate, Alessandro Tredicucci, Jan Devenson, Roland Teissier, Alexei Baranov, Giant intersubband polariton splitting in InAs/AlSb microcavities, Solid State Communications, 142, 311-313 (2007)

4.  Aji A. Anappara,  Alessandro Tredicucci, Fabio Beltram, Giorgio Biasiol and Lucia Sorba, Tunnel-assisted manipulation of intersubband polaritons in asymmetric coupled quantum wells, Applied Physics Letters, 89, 171109 (2006)

3.  Aji A. Anappara,  Alessandro Tredicucci, Fabio Beltram, Giorgio Biasiol and Lucia Sorba, Electrical control of polariton coupling in intersubband microcavities, Applied Physics Letters, 87, 051105 (2005)

2.  Aji A. Anappara,  S. Rajeshkumar, M. Mukundan, P.R.S. Warrier, Swapan Kumar Ghosh, K.G.K. Warrier, Impedance spectroscopic studies of sol-gel derived sub-critically dried silica aerogels, Acta Materialia, 52, 369-375 (2004)

1.  Aji A. Anappara,  S. K. Ghosh, P.R.S. Warrier, K.G.K. Warrier, W. Wunderlich, Impedance spectral studies of sol-gel alumina-silver nanocomposites, Acta Materialia, 51, 3511-3519 (2003)

Theory Courses:

- Solid State Devices (PH4029D)

- Light-matter interaction in resonators (PH4025D)

- Laser Physics (PH4001D)

- Physics of Materials (PH1001D)

Lab Courses:

- General Physics Lab 

-Solid State Physics Lab 

Postdoctoral/Ph.D. positions: 

Highly motivated and talented postdoctoral/doctoral aspirants, please contact aji[at]nitc.ac.in

B.Tech./M.Tech./M.Sc. projects:

Interested students from NITC can contact the group leader to discuss the possible project topics

Dr. Aji A. Anappara is a Professor in the Department of Physics at the National Institute of Technology Calicut. His research focuses on advanced functional materials, optoelectronic devices, and light–matter interactions, with an emphasis on translating fundamental science into practical technologies and patented innovations.

He completed his Ph.D. under the guidance of Prof. Dr. Alessandro Tredicucci at the NEST (National Enterprise for nanoScience and nanoTechnology), Scuola Normale Superiore, Pisa. Following his doctoral studies, he was awarded a prestigious fellowship from the Alexander von Humboldt Foundation, where he worked with Prof. Alfred Leitenstorfer and Prof. Rupert Huber at the University of Konstanz.

He joined the Department of Physics at National Institute of Technology Calicut in November 2010 as an Assistant Professor, and is currently a Professor. His research group works at the interface of nanomaterials, optoelectronics, and ionotronic systems, with contributions spanning high-temperature photodetectors, neuromorphic devices, light-driven chemical processes, and functional low-dimensional materials.

His work has resulted in high-impact publications, multiple patents (granted and filed), and externally funded research projects, reflecting a strong synergy between fundamental science and technological innovation.