Photonic Materials Metrology

The Photonic materials metrology group is working on the use of various organic and inorganic materials to be used in energy harvesting through detection and generation of light. The materials in the  form of nanostrurtures to bulk materials are being manoevered for the detection, guidance, manipulation, amplification and managemnet of light to be used in various applications like metrology and luminescent Security Ink, plasmopnic metamaterials, detectors etc. Though covering all light's technical applications over the whole spectrum, most photonic applications are in the range of UV to NIR region covering the Terahertz regime as well.

The group is actively engaged in the areas of nano photonics, organic photonics and optoelectronics, Ultrafast Optoelectronics & Terahertz Photonics and advanced luminescent materials for security ink.

Theme Projects:

  • Luminescent Security Ink  (Bi-luminescent and OVI Ink)
  • Development of novel inorganic/organic/perovskite materials for optoelectronics application.
  • Size and composition dependent TiO 2 nanoparticles for pigments, paints and coating
  • Ultrafast Optoelectronics & Terahertz Photonics

Activity A: Development of novel inorganic/organic/perovskite materials for optoelectronics application.

Research Projects/current Activities

Working in the general area of organic semiconductor, nanotechnology and 2d materials, which includes the synthesis and characterization of materials, study of electrical, optical and optoelectronic properties and its application in fabrication of devices like organic light emitting diodes, organic photovoltaic cells , organic thin film transistors and Organic light emitting transistors.

Students

Current Students

  1. Dr. Razi Ahamad (CSIR-RA)
  2. Ms. Ritu Verma (RGNF-SRF)
  3. Mr. Asish (CSIR-JRF)
  4. Mr. Surya Tiwari(CSIR-SRF)
  5. Mr. Ramashankar (CSIR-SRF)

Past Students

  • Dr.Amit Kumar
  • Dr. Omwati
  • Dr. Manisha Bajpai
  • Dr. Priyanka Tyagi
  • Dr. Razi Ahmad
  • Dr. Harneet Kaur
  • Dr. Kalpana Agarwal

Facilities:

  • Thin Film growth –Thermal evaporation connected  to glove box-HHV
  • Sputtering-Vac. Tech
  • Spin coating-Laurel Tech
  • Characterization- AFM, STM, Kelvin probe,    
  • Impedance analyser –AC conduction- Solartron 1260,
  • DC conductivity- Keithley-4200, 2400, 2612
  • Steady state and Time resolved PL and Quantum  yield –Horiba
  • Optical absorption- Shimadzu 2401
  • Optical spectrometer  for EL Ocean optics-HR 2000,  HR 4000
  • Liminescence meter-LMT 1009
  • Spectroscopic ellipsometer-Woolam M2000
  • He Cryostats(4K)
  • Probe station-Cascade

Activity B: Ultrafast Optoelectronics & Terahertz Photonics

Our group is working  on the determination of the ultrafast dynamics of various materials to be used for the Organic and inorganic photovoltaics, thermoelectrics etc. The materials being studied are organic semiconductors, polymers, III-V semiconductors, III-N semiconductors, oxide semiconductors, 2D materials etc.

We are also working on the Plasmonics and metamaterals. The plasmonic properties of various nanostructure noble metals are being explored by Ultrafast Pump-probe spectroscopy using femtosecond lasers. These materials are intended to be used for fabrication of detectors in optical, NIR and THz region.

Research ProjectsCurrent Activites    

  • Terahertz generations and detection using photoconductive antenna and non linear crystals.
  • Ultrafast carrier dynamics of organic, inorganic and oxide materials using [ump probe spectroscopy employing femtosecond lasers.
  • Z-scan for the determination of non-linear absorption and refractive index using Femtosceond lasers.
  • Laser induced periodic structure formation for metmaterials and plasmonics.
  • Currently working on the in-house project of Thermoelectrics.
  • Development of solid state refrigerator ~30 o C below ambient

Students:

  1. Ms Chhavi Sharma: A Ph.D. scholar under the “Prime Minister’s Fellowship Scheme for Doctoral Research” (a joint initiative of Confederation of Indian Industry (CII) and Science & Engineering Research Board (SERB)) with the Industry partner Laser Science Services (I) Pvt. Ltd.  Working on ultrafast spectroscopy to study the charge carrier dynamics in plasmonic nano-structures.
  2. Ms Nikita Vashistha: A Junior Research Fellow(JRF) (Electronics) under UGC-NET fellowship. Currently working on ultrafast transient absorption spectroscopy, Femtosecond Laser Etching, Z-scan and UHV thermal deposition system. Areas of interest are plasmonics, non-linear behaviour of materials under Femtosecond laser excitation, design and development of Meta-materials based non-linear devices.

Facilities        

  • Transient  Absorption spectroscopy in the pump-probe configuration using the femtosecond lasers.
  • Z-scan steup with femtosecond laser
  • UHV STM
  • VT112 with AES, EELS, LEED and insitu growth

Transient Absorption spectroscopy in the pump-probe configuration using the femtosecond lasers.

The setup comprise of a Ti: sapphire oscillator (Micra from Coherent ), Ti:sapphire amplifier (Legend from Coherent), Optical Parametric Amplifier (TOPAS form light conversion ) and the spectroscopy system (Helios form Ultrafast Systems). The 4 mJ (1 kHz) output of the amplifier with a pulse width of ~35 fs centered at 800 nm is split into two parts. One of the parts is fed to the OPA with 1.8 mJ energy and the other part with 0.5 mJ is fed to the spectrometer via a delay stage of 0–8 ns. The pulse width after passing through TOPAS is about 70 fs. The broad band white light has been generated inside the spectrometer by passing the split beam through a sapphire and CaF 2 crystals the combination of which is capable of generating probe pulse in the range of 350-1600nm.

UHV-VT STM for the determination of atomic resolution

STM investigation of the Ga-induced cluster on Si(111)-7x7 surface

 

VARIAN Make VT-112 System with AES, EELS and LEED setup along with insitu growth

Ga induced structural changes in Si(111)-7x7  and its phase diagram Varian Make VT-112 system

Activity C: Luminescent Security Ink  (Bi-luminescent and OVI Ink).

One of the major problems with Indian paper currency is that they are prone to easy counterfeiting. Despite the introduction of new currency notes of higher denomination with additional security features, this problem of counterfeiting is still prevalent.  Therefore, it is imperative to introduce novel fool-proof security features in our currency notes, especially for higher denominations, in order to ensure that the counterfeiting becomes nearly impossible. With this premise, CSIR-NPL has come-up with a cost-effective innovation of “bi-luminescent security ink”, which when printed on the currency notes will exhibit two different colors when illuminated by two different wavelength sources of light. The advantage of this technology is that it is cost-effective with all its constituent chemicals easily available in India. This security feature is unique and not currently available on any currency world-wide (US$, Singapore $&, Euro, etc). This technology is cost-effective and developed at a laboratory scale (2 kg batch) but can be scaled up by CSIR-NPL.

Optically variable ink (OVI) is another anti-counterfeiting feature employed in the paper currency of most of the countries. This ink displays two distinct colors depending on the viewing angle of the paper currency, as it reflects various wavelengths of the incident light differently, depending on the angle of incidence to the surface.

OVI is the most novel security feature in Indian currency but this product is totally imported that it only displays changes from one fixed colour (green) to another fixed colour (blue) on varying the viewing angle, thereby incurring a large amount of foreign exchange. As this product technology is monopolized by selected European countries that have protected this invention by filing several hundred patents, they charge exorbitant amount for its import from India. OVI ink developed at CSIR-NPL is totally indigenous and features are highly protected from counterfeiting. This ink can be tailored and engineered to any two desired colours.

Students

Current  Students

Dr. Garima Kedawat, National Postdoctoral Fellow
Dr. Akhilesh Kumar Singh, CSIR-Senior Research Associate
Ms. Indu Sharma, CSIR-Research Associate
Mr. Amit Kumar Gangwar, SRF-CSIR
Mr. Satbir Singh, MANF-JRF
Mr. Pradeep Kumar Kashyap, JRF-CSIR
Mr. Girija Shankar Papanai
Ms. Kanika Nagpal
Ms. Sharon Paul, PhD Intern

Past Students

Dr. Pawan Kumar

Facilities:

Confocal Photoluminescence Mapping System (alpha300M+ spectroscopy function with mapping functionality for 375nm,980nm and 1550nm excitation wavelengths with accessories, WItec).

 

Capabilities: WITec Confocal microscope system with mapping functionality for 375 nm, 980 nm and 1550 nm excitation wavelengths have following salient features:

  • Acquisition of photo luminescence spectra at selected areas
  • Large area spectral mapping up to 25 x 25 mm
  • 3D confocal spectral imaging capability
  • Confocal microscopy in reflection
  • Confocal fluorescence measurement capability
People:

Head:

Dr. Ritu Srivastava, Principal Scientist

 

ritu@nplindia.org
+91-11- 45608644

Scientists:
 

Dr. S. N. Sharma. Principal Scientist

 

Dr. Mahesh Kumar, Senior Scientist

 

Dr. Bipin Kumar, Scientist

 

Dr. S. Rao Ragam, Scientist

 

Ms Reena, Technical Assistant

 
 

shailesh@nplindia.org
+91-11- 45609193

mkumar@nplindia.org
+91-11-45608316(lab), +91-11-45609379 (Office)

guptabgupta@nplindia.org
+91-11-45608284

ragamsr@nplindia.org
+91-11-45608303

reena@nplindia.org

CONTACT INFORMATION