Physics and Astronomy, Materials Science, Electronic, Optical and Magnetic Materials, Surfaces, Coatings and Films
22
Scopus Publications
172
Scholar Citations
8
Scholar h-index
6
Scholar i10-index
Scopus Publications
Synergistic modulation of phonon and charge transport in rare-earth Sm-doped Cu2SnSe3 thermoelectric system Twinkle Gurung, K. Gurukrishna, Rohith Jagan, Yung-Kang Kuo, P. Poornesh, Ashok Rao, Dhanya Sunil Journal of Materials Science Materials in Electronics, 2026 Cu 2 SnSe 3 has attracted a lot of attention as a potential thermoelectric material due to the distinct electrical and thermal characteristics. We report the effect of samarium doping on the Sn site Cu 2 SnSe 3 system. Polycrystalline Cu 2 Sn 1- x Sm x Se 3 (0 ≤ x ≤ 0.08) samples were synthesized by the solid-state method followed by traditional sintering. The low-temperature range of 10–350 K was used to study the electrical transport properties. The lowest resistivity of 0.0024 Ω-cm at 350 K was exhibited by x = 0.08 sample. All the samples’ Seebeck coefficients were found to be positive within the temperature range under investigation, suggesting that most of the charge carriers are holes. With increasing Sm concentration, the resistivity and Seebeck coefficient gradually decreased showing degenerate semi-conducting behaviour. The thermal conductivity also decreased with increasing doping concentration due to the induced defects which enhances the phonon scattering in the Cu 2 SnSe 3 system. Overall, a maximum ZT of 0.017 was achieved for x = 0.08 at 350 K.
Defect engineering via anionic disorders in n-type Bi1.8Sb0.2Te3 alloys: towards enhanced thermoelectric performance at low temperatures K Gurukrishna, Ashok Rao, Han-Yuan Hu, Yung-Kang Kuo, Poornesh P Physica Scripta, 2025 We report on the defect engineering in n-type Bi1.8Sb0.2Te3 end-compound via Te non-stoichiometry (Bi1.8Sb0.2Te3−x ) intending to enhance the thermoelectric performance at low and near room temperature regime (10–350 K). Contemplating the asymmetry in electronic and phonon transport, the extrinsic anionic disorders successfully modulate the thermoelectric transport. Systematic manipulation of Te and Bi/Sb vacancies increases the electrical conductivity, leading to the highest power factor of 534 μW mK−2 at 350 K. The self-doping effect created via anionic disorders resulted in an enhancement in the thermoelectric performance compared to the Bi1.8Sb0.2Te3 compound. Increased ZT values, accompanied by the thermoelectric quality factor, confirm the quality factor as one of the decisive parameters in elevating the thermoelectric performance. The sample with x = 0.08 has the highest ZT value of 0.081 at 350 K. A 174% increase in compatibility factor is also observed, indicating the state-of-the-art applicability of Bi1.8Sb0.2Te3 in segmented thermoelectric generators.
Optimising thermoelectric transport in n-type Bi1.8Sb0.2Te3 alloys via isovalent Y doping G Poojitha, Gurukrishna K, Deepika Shanubhogue U, Poornesh P, Ashok Rao, Ma Eunice de Anda Reyes, Umapada Pal Materials Research Express, 2025 This study explores the thermoelectric properties of isovalent Y-doped Bi1.8−x Y x Sb0.2Te3 at various doping levels (x = 0.04, 0.08, 0.12) prepared using the solid-state reaction method. X-ray diffraction (XRD) analysis confirmed a rhombohedral structure with the R 3 ̅ m space group. The SEM micrographs provide evidence of lamellar-textured samples characterized by minimal porosity. The electrical resistivity of compounds demonstrated typical behavior of degenerate semiconductors, showing an increase with rising temperature. Seebeck coefficient and Hall effect measurements identified electron-dominant charge carriers, with the Seebeck coefficient displaying a consistent increase across the temperature range of 30 to 310 K. This behavior implies a uniform density of states and a stable position of Fermi energy within the samples, and it is verified from the computational studies which shows the similar band gap values. The pristine sample achieved the highest power factor (PF) of 197 μW mK−2 at 310 K. Optimized Y doping significantly reduces the thermal conductivity of Bi1.8Sb0.2Te3 due to enhanced phonon scattering caused by point defects. Notably, 40% increase in ZT compared to pristine with the highest value of 0.17 at 310 K, for the x = 0.12 sample.
Oxygen Plasma-Induced Modification of Structural and Electrical Properties of Pr0.5Sr0.5MnO3 Manganites Pronita Chettri, Bhakta Kunwar, Gurukrishna Bhatt, Suraj Mangavati, Arun Kumar Sarma, Gunadhor S. Okram, Devaraja Chinnappareddy, Ashok Rao, Utpal Deka Physica Status Solidi A Applications and Materials Science, 2024 Herein, the impact of exposing the perovskite compound Pr0.5Sr0.5MnO3 to oxygen plasma is explored by comparing the structural and transport properties of the exposed samples to those of the unexposed ones. The Pr is oxidized to PrO2 in the investigated samples due to plasma exposure. The alterations in the transport properties can be linked to the changes in MnOMn bond angle and MnO bond length due to plasma exposure, as indicated by X‐ray diffraction analysis. Additionally, exposure to oxygen plasma increases the conductivity by incorporating oxygen into the exposed samples, making them oxygen‐rich. Detailed analysis of the resistivity and thermoelectric power data indicates that small polarons are responsible for conduction at high temperatures, while at low temperatures, variable range polarons take over. The negative value of the thermopower at all temperatures proclaims that the electrons behave as the dominant charge carriers.
Tunable insulator-metal transition in epitaxial VO2 thin films via strain and defect engineering Aditya Kamat, Gurukrishna K., Rishow Kumar, Abhishek Mishra, Amit Kumar Verma, Shivam Tripathi, Ashish Garg, Shikhar Misra Nanoscale Advances, 2024 The correlation between Tc, axial strain and oxygen vacancies is investigated for SMT, and DFT insights are reported for PLD grown VO2 epilayers on c-Al2O3.
Development and Analysis of Current Collectors for Proton Exchange Membrane Fuel Cells Aneesh Jose, Sudesh Bekal, Deepika Shanubhogue U, Gurukrishna K Advances in Science and Technology Research Journal, 2024 Hydrogen fuel cells are gaining popularity in power-consuming devices due to their zero-emission characteristics. However, ohmic resistance, which arises from the resistance to electron flow through the electrodes and exter - nal circuit, can cause reduced efficiency and voltage drops in a fuel cell. This research aims to develop current collector plates for proton exchange membrane fuel cells with optimal design, high electrical conductivity, and thermal conductivity to mitigate ohmic resistance. Six different designs and five different materials-copper, brass, aluminum, stainless steel 316, and stainless steel 304 – were considered for this purpose. The study involved experimental electrical conductivity and fuel cell performance tests to identify the best material and design for the current collector. Results indicated that brass and copper exhibited the least resistivity and favorable material characteristics. Consequently, all six current collector plate designs were developed using brass and copper with various machining and finishing processes. Performance testing on a fuel cell test station revealed that brass cur - rent collector plate design 5, featuring open ratios, demonstrated superior performance. Ultimately, the optimum design and material selection of the current collector plates have led to the development of fuel cells with reduced ohmic resistance and improved overall performance.
Wide-Range Tuning of Insulator–Metal Transition via Microstructure and Defect Engineering of Sputtered VO 2 Thin Films AK Rana, G K, HN Joshi, AU Kamat, S Misra Crystal Growth & Design , 2026 2026
Tunable insulator–metal transition in VO2-based nanocomposite thin films via strain and defect engineering A Kamat, G K, R Kumar, A Garg, S Misra APL Electronic Devices 2 (1), 016103 , 2026 2026 Citations: 1
Defect engineering via anionic disorders in n-type Bi 1.8 Sb 0.2 Te 3 alloys: towards enhanced thermoelectric performance at low temperatures K Gurukrishna, A Rao, HY Hu, YK Kuo, P P Physica Scripta 100 (5), 055943 , 2025 2025 Citations: 2
Optimising thermoelectric transport in n-type Bi 1.8 Sb 0.2 Te 3 alloys via isovalent Y doping G Poojitha, G K, D Shanubhogue U, P P, A Rao, ME de Anda Reyes, ... Materials Research Express 12 (4), 045504 , 2025 2025
Strain evolution and in situ phase transitions in freestanding BaTiO 3 epitaxial membranes via a La 2/3 Sr 1/3 MnO 3 sacrificial layer K Gurukrishna, AU Kamat, R Kumar, A Garg, S Misra RSC advances 15 (56), 47946-47954 , 2025 2025
Investigations on the impact of nickel doping on thermoelectric properties in n-type Bi 1.8 Sb 0.2 Te 3 alloy G Poojitha, K Gurukrishna, NV Srihari, P Poornesh, K YK RSC advances 15 (41), 34211-34224 , 2025 2025
Mott–vanadium dioxide-based memristors as artificial neurons for brain-inspired computing: a view on current advances K Gurukrishna, AU Kamat, S Misra Journal of Materials Chemistry C 13 (3), 1013-1035 , 2025 2025 Citations: 16
Enhancement of multiferrocity in CuCrO2 compounds through effective doping induced optimization of localized carrier holes and reduction in helical disorder N Barot, PK Mehta, BS Bishnoi, S Bhattacharjee, A Rao, R Thomas, ... Physica B: Condensed Matter 695, 416559 , 2024 2024
Oxygen Plasma‐Induced Modification of Structural and Electrical Properties of Pr 0.5 Sr 0.5 MnO 3 Manganites P Chettri, B Kunwar, G Bhatt, S Mangavati, AK Sarma, GS Okram, ... physica status solidi (a) 221 (20), 2400436 , 2024 2024 Citations: 3
Tunable insulator–metal transition in epitaxial VO 2 thin films via strain and defect engineering A Kamat, K Gurukrishna, R Kumar, A Mishra, AK Verma, S Tripathi, ... Nanoscale Advances 6 (22), 5625-5635 , 2024 2024 Citations: 16
Development and Analysis of Current Collectors for Proton Exchange Membrane Fuel Cells A Jose, S Bekal, UD Shanubhogue, K Gurukrishna Advances in Science and Technology. Research Journal 18 (6) , 2024 2024 Citations: 1
Role of sintering temperature in modulating the charge transport of BiCuSeO thermoelectric system: correlations to the microstructure NP Madhukar, K Gurukrishna, BR Bhat, UD Shanubhogue, S Mangavati, ... Applied Physics A 130 (1), 55 , 2024 2024 Citations: 4
Superior thermoelectric performance in non-stoichiometric Cu3SbSe4 system: Towards synergistic optimization of carrier and phonon transport K Gurukrishna, A Rao, S Prasad, YC Wang, YK Kuo Materials Research Bulletin 167, 112434 , 2023 2023 Citations: 5
Thermoelectric Composite of (Bi 0.98 In 0.02 ) 2 Te 2.7 Se 0.3 /Bi 2 Se 3 with Enhanced Thermopower and Reduced Electrical Resistivity GS Hegde, AN Prabhu, S Putran, A Rao, K Gurukrishna, ... Journal of Electronic Materials 52 (6), 3749-3758 , 2023 2023 Citations: 2
Enhancement of low-temperature thermoelectric performance via Pb doping in Cu3SbSe4 A Pal, KS Prasad, K Gurukrishna, S Mangavati, P Poornesh, A Rao, ... Journal of Physics and Chemistry of Solids 175, 111197 , 2023 2023 Citations: 15
BiCuSeO/GdH 2 thermoelectric composite: a p-type to n-type promoter with superior charge transport RB Bhoomika, K Gurukrishna, NP Madhukar, UD Shanubhogue, A Rao, ... Journal of Materials Science: Materials in Electronics 34 (8), 775 , 2023 2023 Citations: 3
Enhancement of thermoelectric power factor in Cu 2 Se superionic conductor via high energy electron beam irradiation S Mangavati, K Gurukrishna, A Rao, VC Petwal, VP Verma, J Dwivedi Journal of Materials Science: Materials in Electronics 34 (2), 87 , 2023 2023 Citations: 8
Enhancement of power factor of screen printed polyaniline/graphite based flexible thermoelectric generator by structural modifications R Nayak, P Shetty, M Selvakumar, A Rao, KM Rao, K Gurukrishna, ... Journal of Alloys and Compounds 922, 166298 , 2022 2022 Citations: 26
Investigation of near-room and high-temperature thermoelectric properties of (Bi 0.98 In 0.02 ) 2 Se 2.7 Te 0.3 /Bi 2 Te 3 composite system GS Hegde, AN Prabhu, A Rao, K Gurukrishna, U Deepika Shanubhogue Journal of Materials Science: Materials in Electronics 33 (33), 25163-25173 , 2022 2022 Citations: 7
On the high-energy electron beam irradiation-induced defects in Cu2SnSe3 system: an effort towards modifying the structure, microstructure, and thermoelectric transport K Gurukrishna, S Mangavati, A Rao, P Poornesh, VC Petwal, VP Verma, ... Journal of Materials Science: Materials in Electronics 33 (28), 22270-22280 , 2022 2022 Citations: 7
MOST CITED SCHOLAR PUBLICATIONS
Enhancement of thermoelectric performance by tuning selenium content in the Cu2SnSe3 compound K Gurukrishna, A Rao, ZZ Jiang, YK Kuo Intermetallics 122, 106803 , 2020 2020 Citations: 33
Enhancement of power factor of screen printed polyaniline/graphite based flexible thermoelectric generator by structural modifications R Nayak, P Shetty, M Selvakumar, A Rao, KM Rao, K Gurukrishna, ... Journal of Alloys and Compounds 922, 166298 , 2022 2022 Citations: 26
Mott–vanadium dioxide-based memristors as artificial neurons for brain-inspired computing: a view on current advances K Gurukrishna, AU Kamat, S Misra Journal of Materials Chemistry C 13 (3), 1013-1035 , 2025 2025 Citations: 16
Tunable insulator–metal transition in epitaxial VO 2 thin films via strain and defect engineering A Kamat, K Gurukrishna, R Kumar, A Mishra, AK Verma, S Tripathi, ... Nanoscale Advances 6 (22), 5625-5635 , 2024 2024 Citations: 16
Enhancement of low-temperature thermoelectric performance via Pb doping in Cu3SbSe4 A Pal, KS Prasad, K Gurukrishna, S Mangavati, P Poornesh, A Rao, ... Journal of Physics and Chemistry of Solids 175, 111197 , 2023 2023 Citations: 15
Existence of Partially Degenerate Electrical Transport in Intermetallic Cu 2 SnSe 3 Thermoelectric System Sintered at Different Temperatures K Gurukrishna, HR Nikhita, SMM Swamy, A Rao Metals and Materials International 28 (8), 2023-2032 , 2022 2022 Citations: 15
Enhancement of thermoelectric power factor in Cu 2 Se superionic conductor via high energy electron beam irradiation S Mangavati, K Gurukrishna, A Rao, VC Petwal, VP Verma, J Dwivedi Journal of Materials Science: Materials in Electronics 34 (2), 87 , 2023 2023 Citations: 8
Manipulating the phonon transport towards reducing thermal conductivity via replacement of Cu by Mn in Cu2SnSe3 thermoelectric system K Gurukrishna, A Rao, YC Chung, YK Kuo Journal of Solid State Chemistry 307, 122755 , 2022 2022 Citations: 8
Investigation of near-room and high-temperature thermoelectric properties of (Bi 0.98 In 0.02 ) 2 Se 2.7 Te 0.3 /Bi 2 Te 3 composite system GS Hegde, AN Prabhu, A Rao, K Gurukrishna, U Deepika Shanubhogue Journal of Materials Science: Materials in Electronics 33 (33), 25163-25173 , 2022 2022 Citations: 7
On the high-energy electron beam irradiation-induced defects in Cu2SnSe3 system: an effort towards modifying the structure, microstructure, and thermoelectric transport K Gurukrishna, S Mangavati, A Rao, P Poornesh, VC Petwal, VP Verma, ... Journal of Materials Science: Materials in Electronics 33 (28), 22270-22280 , 2022 2022 Citations: 7
Superior thermoelectric performance in non-stoichiometric Cu3SbSe4 system: Towards synergistic optimization of carrier and phonon transport K Gurukrishna, A Rao, S Prasad, YC Wang, YK Kuo Materials Research Bulletin 167, 112434 , 2023 2023 Citations: 5
Role of sintering temperature in modulating the charge transport of BiCuSeO thermoelectric system: correlations to the microstructure NP Madhukar, K Gurukrishna, BR Bhat, UD Shanubhogue, S Mangavati, ... Applied Physics A 130 (1), 55 , 2024 2024 Citations: 4
Oxygen Plasma‐Induced Modification of Structural and Electrical Properties of Pr 0.5 Sr 0.5 MnO 3 Manganites P Chettri, B Kunwar, G Bhatt, S Mangavati, AK Sarma, GS Okram, ... physica status solidi (a) 221 (20), 2400436 , 2024 2024 Citations: 3
BiCuSeO/GdH 2 thermoelectric composite: a p-type to n-type promoter with superior charge transport RB Bhoomika, K Gurukrishna, NP Madhukar, UD Shanubhogue, A Rao, ... Journal of Materials Science: Materials in Electronics 34 (8), 775 , 2023 2023 Citations: 3
Defect engineering via anionic disorders in n-type Bi 1.8 Sb 0.2 Te 3 alloys: towards enhanced thermoelectric performance at low temperatures K Gurukrishna, A Rao, HY Hu, YK Kuo, P P Physica Scripta 100 (5), 055943 , 2025 2025 Citations: 2
Thermoelectric Composite of (Bi 0.98 In 0.02 ) 2 Te 2.7 Se 0.3 /Bi 2 Se 3 with Enhanced Thermopower and Reduced Electrical Resistivity GS Hegde, AN Prabhu, S Putran, A Rao, K Gurukrishna, ... Journal of Electronic Materials 52 (6), 3749-3758 , 2023 2023 Citations: 2
Tunable insulator–metal transition in VO2-based nanocomposite thin films via strain and defect engineering A Kamat, G K, R Kumar, A Garg, S Misra APL Electronic Devices 2 (1), 016103 , 2026 2026 Citations: 1
Development and Analysis of Current Collectors for Proton Exchange Membrane Fuel Cells A Jose, S Bekal, UD Shanubhogue, K Gurukrishna Advances in Science and Technology. Research Journal 18 (6) , 2024 2024 Citations: 1
Wide-Range Tuning of Insulator–Metal Transition via Microstructure and Defect Engineering of Sputtered VO 2 Thin Films AK Rana, G K, HN Joshi, AU Kamat, S Misra Crystal Growth & Design , 2026 2026
Optimising thermoelectric transport in n-type Bi 1.8 Sb 0.2 Te 3 alloys via isovalent Y doping G Poojitha, G K, D Shanubhogue U, P P, A Rao, ME de Anda Reyes, ... Materials Research Express 12 (4), 045504 , 2025 2025
