Scientist's Profile

Research Interest

• Energy Materials and Devices
• Growth, Fabrication and Measurements of optoelectronic Devices
• Oxide heterostructures
• 2-D Van der Waals Materials

Present Activity: Our main focus on novel functional epi-layers, nanomaterials, nanostructures and devices for optoelectronics and energy applications. We also study the electronic structure of ceramics, composite materials, transition metal-oxides, oxide heterostructures and 2-dimensional layered materials by using photoelectron spectroscopy.

Presently, our main scope is on the development of ceramic separators for Li-ion/Li battery. We also study the growth, fabrication and measurements of ultra-sensitive optoelectronic photodetectors.

Recent Research and Development:

Highly resistive GaN/r-GO based photodetector for Harsh Electronics applications:

Broadband ultraviolet photodetector based on hybrid 2D/3D structure was demonstrated. The device employed a highly resistive GaN integrated with thin reduced graphene‐oxide for applications in harsh environments, working up to ±200 V bias and 116 °C with long‐term stability over 28 months without any aging effect. The device operates appreciably in both photovoltaic and photoconductive modes showing high responsivity and fast switching speed. (Advanced Optical Materials 7, 1900340, 2019)

Graphitic-C₃N₄/Si Binary Multifunctional Photodetector:

A novel binary photoswitching over an ultrabroadband range was demonstrated. The device employs a hybrid 2D/3D structure based on silicon platform which opens up a possibility for the application of graphitic carbon‐nitride (g‐C3N4) nanosheets for light‐based binary communications, interconnects for optical computing and weak signal detections. This also significantly improve the performance of silicon solar cells. Covered by online scientific media (Advanced Optical Materials 6, 1800191 2018); highlighted in “Nature India” https://www.natureasia.com/en/nindia/article/10.1038/nindia.2018.76

Self-powered Ultraviolet Photodetector:

Fabrication of high-performance photodetectors using molecular beam epitaxy grown GaN is quite challenging & extremely costly. It is thus very essential to develop simple and cost effective fabrication routes to facilitate their large-scale deployment. This works successfully demonstrated non-cleanroom fabrication of a hybrid device (r-GO/GaN) that works in self-powered mode for ultra-violet detection (Applied Physics Letters 109, 242102, 2016).

Electronic Structure of oxide heterostructures guided by electronic reconstruction revealed by Photoelectron Spectroscopy:

The electronic structure of high quality epitaxial 6 unit cells LaAl_1-xCr _xO₃ (x = 0, 0.2, 0.4, 0.6 and 1.0) on TiO₂ terminated SrTiO₃ substrates were grown by pulsed laser deposition technique. We have found multiple valence states of both Ti and Cr ions, where an inverse proportionality was observed between the Ti³⁺ and Cr²⁺ valence states concentration with increasing x. The progressive increase in the concentration of Cr²⁺ valence states with the progressive decrease in the concentration of Ti³⁺ valence states as a function of x and the complete disappearance of Ti³⁺ states for x ³ 0.6, indicates electronic reconstruction is the most important and universal mechanism for quasi-two-dimensional electron gas in these oxides heterostructures (Physical Review B, 91, 115127, 2015).

No. of Publications:

Recent Selected Publications (* as corresponding author)

• Direct measurement of interfacial Dzyaloshinskii-Moriya interaction at the few-layer MoS₂/Ni₈₀Fe₂₀ interface, A. Kumar, A. Chaurasiya, N. Chowdhury, A. Mondal, R. Bansal, A. Barvat, S. P. Khanna, Pal, S. Chaudhary, A. Barman and P. K. Muduli. Applied Physics Letters 116, 232405 (2020).
• Solution-Processed-2D on 3D Heterojunction UV-Visible Photodetector for Low-Light Applications, G. Kumar, N. Prakash, M. Singh, A. Chakravorty, D. Kabiraj, S. P. Singh, Pal*, and S. P. Khanna, ACS Appl. Electron. Mater. 1, 1489, (2019).
• Long‐Term, High‐Voltage, and High‐Temperature Stable Dual‐Mode, Low Dark Current Broadband Ultraviolet Photodetector Based on Solution‐Cast r‐GO on MBE‐Grown Highly Resistive GaN, N. Prakash, G. Kumar, M. Singh, S. P. Singh, B. Satpati, S. P. Khanna, Pal*, Advanced Optical Materials 7, 1900340, (2019).
• Binary Multifunctional Ultrabroadband Self-Powered g-C₃N₄/Si Heterojunction High-Performance Photodetector, N. Prakash, G. Kumar, M. Singh, A. Barvat, Pal*, S. P. Singh, H. K. Singh and S. P. Khanna, Advanced Optical Materials 6, 1800191, (2018).
• Electronic structure of the PLD grown mixed phase MoS₂/GaN interface and its thermal annealing effect, A. Barvat, N. Prakash, G. Kumar, D. K. Singh, A. Dogra, S. P. Khanna, and Pal*, Current Applied Physics 18, 170, (2018).
• Emerging photoluminescence from bilayer large-area 2D MoS₂ films grown by pulsed laser deposition on different substrates, Barvat, N. Prakash, B. Satpati, S. S. Singha, G. Kumar, D. K. Singh, A. Dogra, S. P. Khanna, A. Singha, P. Pal*, Journal of Applied Physics 122, 015304 (2017).
• Photo-resistive properties of LaAl₆Cr_0.4O₃/SrTiO₃ heterostructures: a comparative study with LaAlO₃/SrTiO₃, Aswin V., P. Kumar, P. Pal* and A. Dogra, Optics Letters 41, 1134 (2016).
• Ultrasensitive self-powered large area planar GaN UV-photodetector using reduced graphene oxide electrodes. N. Prakash, M. Singh, G. Kumar, A. Barvat, K. Anand, P. Pal*, P. Singh and S. P. Khanna. Applied Physics Letters 109, 242102 (2016).
• Metal-to-insulator transition inLaAl_1−xCr_xO₃/SrTiO₃ oxide heterostructures guided by electronic reconstruction, P. Kumar,  Pal*, A. K. Shukla, J. J. Pulikkotil, and A. Dogra, Phys. Rev. B 91, 115127 (2015).
• Chemical potential shift and gap-state formation in SrTiO_3-d revealed by photoemission spectroscopy, Pal*, P. Kumar, Aswin V, A. Dogra and A. G. Joshi, Journal of Applied Physics 116, 053704 (2014).
• Photoconductivity and photo-detection response of multiferroic bismuth iron oxide. A. Anshul, H. Borkar, P. Singh, Pal, S. S. Kushvaha and A. Kumar; Applied Physics Letters 104, 132910 (2014).
• Electronic structure of the electron-doped CMR Ca₈₆Pr_0.14MnO_3. M. K. Dalai, P. Pal, B. R. Sekhar, M. Merz, P. Nagel, S. Schuppler, and C. Martin, Phys. Rev. B 85, 155128 (2012).
• A simple method to produce almost perfect graphene on highly oriented pyrolytic graphite. M. J. Webb, P. Palmgren, Pal, O. Karis and H. Grennberg, Carbon 49, (2011) 3242-3249.
• Pseudogap behavior in Pr₅Sr_0.5MnO₃: A photoemission study. P. Pal*, M. K. Dalai and I. Ulfat, Surface Science 605, 875-877 (2011).
• Atomic scale chemical fluctuation in LaSrVMoO₆: A proposed halfmetallic antiferromagnet. S. Jana, V. Singh, S. D. Kaushik, C. Meneghini, Pal, R. Knut, O Karis, I. Dasgupta, V. Siruguri, S. Ray, Phys. Rev. B (Rapid Communications) 82, 180407(R) (2010).
• Pseudogap behavior of phase-separated Sm_1-xCa_xMnO₃: A comparative photoemission study with double exchange. Pal, M. K. Dalai, R. Kundu, B. R. Sekhar and C. Martin, Phys. Rev. B. 77, 184405 (2008).
• Near Fermi Level Electronic Structure of Pr_1-xSr_xMnO₃: Photoemission study. Pal, M. K. Dalai, R. Kundu, M. Chakraborty, B. R. Sekhar and C. Martin, Phys. Rev. B 76, 195120 (2007).
• Electronic structure of Pr₆₇Ca_0.33MnO₃ near the Fermi level studied by ultraviolet photoelectron and x-ray absorption spectroscopy. M. K. Dalai, P. Pal, B. R. Sekhar, N. L. Saini, R. K. Singhal, K. B. Garg, B. Doyle, S. Nanarone, C. Martin, and F. Studer, Phys. Rev. B 74, 165119 (2006).
• Valence band electronic structure of Pr_1-xSr_xMnO₃ from photoemission studies. Pal, M. K. Dalai, B. R. Sekhar, S. N. Jha, S. V. N. Bhaskara Rao, N. C. Das, C. Martin, and F. Studer, J. Phys. Condens. Matter 17, (2005) 2993-2999.

Recently delivered invited talks and session chair:

[7] Delivered series lectures in the faculty development program at Jaypee Institute of Information Technology (JIIT) – Noida, 01-06^th July, 2019, organized by department of Physics and Materials Science & Engineering, JIIT, title: “Familiarization with X-ray Photoelectron Spectroscopy (XPS) method and technique”

[6] Delivered an invited talk on 16^th March, 2018 at Jaypee Institute of Information Technology (JIIT) – Noida in the National Conference on Advanced Materials and Nanotechnology (AMN-2018) 15-17^th March 2018, organized by department of Physics and Materials Science & Engineering, JIIT, title: “Two-Dimensional (2D)-MoS₂ Layered Materials: Electronic Structure and Optoelectronic Devices”

[5] Delivered an invited talk on 27^th December, 2017 at IISER-Bhopal in the National Conference on Electronic Structure (NCES-2017) Organized by TIFR, IOP and SINP, title: “Two-Dimensional (2D) MoS₂ Layered Materials: Electronic Structure and Optoelectronic Devices”

[4] Delivered an invited talk on 17^th March, 2017 title: “Oxide thin films and Optoelectronic Devices”, during 16-17^th, 2017, LEOS (Laboratory for Electro-Optics System), ISRO, Peenya, Karnataka, Bangalore, India

[3] Delivered an invited speech on 23^rd Sept, 2016 at UGC Sponsored National Level Seminar on “Characterization of Nanomaterials” Organized by Dept. of Physics, Ramananda College, Bishnupur, Bankura W.B, during September 22-23, 2016 title: “Introduction to X-ray Photoelectron spectroscopy and Photoconductivity on material characterization”

[2] Session Chair at UGC Sponsored National Level Seminar on “Characterization of Nanomaterials” Organized by Dept. of Physics, Ramananda College, Bishnupur, Bankura W.B, during September 22-23, 2016.

[1] Delivered an invited talk on 23^rd Feb, 2016 title: “Interface properties of oxide heterostructures”, at Workshop on Frontiers in Condensed Matter Physics” in Feb. 22^nd – 27^th, 2016 at IOP, Bhubaneswar, India.

…..full list

Current Projects:

1. Energy Storage Platform on Batteries, sponsored by DST, Co-principal investigator (August 2019 to July 2023), Scope: Development of Ceramic Separators for Li-ion battery

Completed Projects: Four

4. Growth & Characterization of III-nitride Hetero-structures for Solid State Lighting devices, under Efficient Silicon Photovoltics with Smart Electronics and Lighting System a network project sponsored by CSIR under Technologies and Products for Solar-energy Utilization through Networks- “TAP-SUN” 2012-2017 (Team member)
5. MBE grown GaN/In_xGa_1-xN high efficiency multi junction Solar cell, under the project entitled Development of Advanced Materials for Next Generation Energy Efficient Devices (D-NEED) PSC0109 funded by CSIR under 12th FYP 2012-2017 (Team member)
6. Photoconductivity of novel materials – Exploiting new experimental resources, funded by CSIR-NPL, LRF (OLP 120132) 2011-2015: “Variable Temperature Steady State Photoconductivity” facility was developed in this project at CSIR-NPL (Principal Investigator)
7. Fabrication of LED Devices and Systems for Solid State Lighting (NWP-25), A supra-institutional network project sponsored by CSIR under 11^th FYP 2007-2012 (Team member)

Ph. D Supervision:

1. Samanta Pal, CSIR NET JRF (Date of joining July 2020)
2. Modassar Hossain, CSIR NET JRF (Date of joining August 2019)

Ph. D degree awarded (AcSIR): 02

 M. Tech thesis completed: 04

Openings:

Ph. D Position: We are looking for an application from motivated CSIR-NET qualified students for Ph. D program in our group from Physics or Chemistry or Engineering background. Eligible NET qualified students may contact prabir.p@cgcri.res.in

Postdoctoral Research Associated Position: We are looking for postdoctoral researcher in our group. Candidates interested in applying for a fellowship (NPDF or other) may contact. Interested Ph. D students may contact directly with a CV, list of publications and very brief past research activities.

Short Term Project: Interested students may apply for short term project.