Dr. Venkatraman
@citchennai.edu.in
Chennai Institute of Technology, Chennai
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Materials Chemistry, Surfaces, Coatings and Films, Renewable Energy, Sustainability and the Environment
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ananthan Mevani Raju and M.R. Venkatraman
Elsevier BV
D. Vinoth Pandi, V. Saraswathi, M.R. Venkatraman, N. Muthukumarasamy, S. Agilan, D. Velauthapillai, K. Brindhadevi, and A. Pugazhendhi
Elsevier BV
Nandhakumar Eswaramoorthy, Ravuri Syamsai, Senthilkumar Nallusamy, Selvakumar Pitchaiya, and M. R. Venkatraman
Springer Nature Singapore
E. Nandhakumar, P. Selvakumar, A. Arulraj, E. Vivek, M.R. Venkatraman, A. Sasikumar, M. Prem Kumar, R.V. Mangalaraja, R. Kamatchi, and N. Senthilkumar
Elsevier BV
Jayaprakash Madhu, Venkatraman Madurai Ramakrishnan, Agilan Santhanam, Muthukumarasamy Natarajan, Balraju Palanisamy, Dhayalan Velauthapillai, Nguyen Thuy Lan Chi, and Arivalagan Pugazhendhi
Elsevier BV
Venkatraman Madurai Ramakrishnan, G. Rajesh, P. Selvakumar, M. Flores, N. Muthukumarasamy, Dhayalan Velauthapillai, Nguyen Thuy Lan Chi, and Arivalagan Pugazhendhi
Elsevier BV
Selvakumar Pitchaiya, Nandhakumar Eswaramoorthy, Venkatraman Madurai Ramakrishnan, Muthukumarasamy Natarajan, and Dhayalan Velauthapillai
American Chemical Society (ACS)
In the emerging photovoltaic (PV) technologies, the golden triangle rule includes higher efficiency, longevity (or stability), and low cost, which are the foremost criteria for the root of commercial feasibility. Accordingly, a unique low-cost, ecofriendly, all-solution-processed, "bio-inspired" graphitic carbon (extracted from the most invasive plant species of Eichhornia crassipes: listed as one of the 100 most dangerous species by the International Union for Conservation of Nature) and a mixed halide perovskite interface-engineered, unique single-cell large-scale (10 × 10 sq.cm with an active area of 88 cm2) carbon-based perovskite solar cell (C-PSC) are demonstrated for the first time, delivering a maximum PCE of 6.32%. Notable performance was observed under low light performance for the interface-engineered champion device fabricated using the layer-to-layer approach, which, even when tested under fluorescent room light condition (at 200 lux of about ∼0.1 SUN illumination), exhibited a significant PCE. In terms of addressing the stability issues in the fabricated PSC devices, the present work has adopted a two-step strategy: the instability toward the extrinsic factors is addressed by encapsulation, and the subsequent intrinsic instability issue is also addressed through interfacial engineering. Surprisingly, when tested under various stability conditions (STC) such as ambient air, light (continuous 1 SUN, under room light illumination (0.1 SUN) and direct sunlight), severe damp up to a depth of ∼25 mm water (cold (∼15 °C) and hot (∼65 °C)), acidic pH (∼5), and alkaline pH (∼11)) conditions, the fabricated large-scale carbon-based perovskite solar cells (C-LSPSCs) retained unexpected long-term stability in their performance for over 50 days. As to appraise the performance superiority of the fabricated C-LSPSC devices under various aforesaid testing conditions, a working model of a mini-fan has been practically powered and demonstrated.
Jayaprakash Madhu, Venkatraman Madurai Ramakrishnan, Pavithrakumar Palanichamy, Agilan Santhanam, Muthukumarasamy Natarajan, Peulakumari Ponnaian, Kathirvel Brindhadevi, Arivalagan Pugazhendhi, and Dhayalan Velauthapillai
Elsevier BV
Rajkumar Senthamarai, Venkatraman Madurai Ramakrishnan, Prabhu Murugan, Anbarasan Ponnusamy Munusamy, and Suguna Kulandhaivel
Hindawi Limited
Photoanodes of TiO2 and Nickel (Ni) doped TiO2 nanoparticles (Ni‐TiO2 NPs) were prepared by Bio‐assisted synthesis technique using the extract of grapefruit as solvent/reducing agent. From XRD and Raman analysis the anatase phase of the prepared TiO2 NPs and Ni‐TiO2 NPs were confirmed. The morphology of the prepared NPs was analyzed using FESEM analysis, from the analysis nanorods and spherical shaped structures were observed for TiO2 and Ni‐TiO2, respectively. The optical properties of the synthesized TiO2 and Ni‐TiO2 NPs have been studied by UV‐Vis spectroscopy and the absorption in the visible region was observed for the Ni doped TiO2 samples. Using the prepared TiO2 and Ni‐TiO2 NPs as photo anodes DSSCs were constructed and its performance was examined. In this study, two different kinds of dyes were used as sensitizers such as natural dye and commercial dye (N719). The natural sensitizers are extracted from the murrayakoenigii fruit (MKF) skin. The nickel doped TiO2 nanoparticle showed an efficiency (η) of 2.25% for MKF dye and 5.08% for N719 with 0.05 M of nickel doping.
S. Rajkumar, M. R. Venkatraman, K. Suguna, P. Karuppasamy, M. Senthil Pandian, and P. Ramasamy
Springer Science and Business Media LLC
S. Rajkumar, M.R. Venkatraman, P. Balraju, K. Suguna, and Arivalagan Pugazhendhi
Elsevier BV
Venkatraman Madurai Ramakrishnan, Muthukumarasamy Natarajan, Selvakumar Pitchaiya, Agilan Santhanam, Dhayalan Velauthapillai, and Arivalagan Pugazhendhi
Hindawi Limited
By the process of doping in semiconducting nanomaterials, properties of the materials such as electronic, optical and photochemical properties can be effectively tuned. Here fluorine doped TiO2 nanostructures were synthesized by microwave assisted solvothermal technique. The X‐ray diffraction patterns (XRD) and Raman analysis results of the sample exhibits peaks characteristic of anatase TiO2. From the UV‐visible absorption analysis, an increase in visible light absorption with no significant change in the absorption edge was noticed. F doped TiO2 nanostructures were found to possess quasi cubic morphology through the transmission electron microscope images and from the presence of well‐defined ring pattern in selected area electron diffraction patterns the polycrystalline nature of the samples were confirmed. The presence of fluorine in the TiO2 lattice was confirmed through the presence of Ti3+ states using X‐ray photoelectron spectroscopy (XPS) analysis and electron paramagnetic resonance (EPR) analysis respectively. The prepared TiO2, F doped TiO2 nanostructures were coated over fluorine doped tin oxide (FTO) substrates, further they were subjected to dye sensitization and were used as photoanodes in dye sensitized solar cells and their power conversion efficiencies were studied.
Venkatraman Madurai Ramakrishnan, Muthukumarasamy N., Selvakumar Pitchaiya, Agilan S., Arivalagan Pugazhendhi, and Dhayalan Velauthapillai
Hindawi Limited
Electron transport layer is one of the important layer in the dye‐sensitized solar cells (DSSCs) which is responsible for the transport of photo‐generated electrons by the dye to the outer circuit. TiO2 has been widely used as electron transport material in DSSCs. However, improving the electrical conductivity of TiO2 without sacrificing the surface area is one of the important strategies to improve the efficiency of the DSSCs. Here graphene oxide (GO) is added as an additive into the TiO2 network towards the preparation of TiO2/reduced graphene oxide (RGO) composites by UV assisted photocatalytic reduction method. The RGO/TiO2 composites with different compositions of RGO were characterized and the performance of DSSCs using the prepared material as photoanode was studied. Furthermore, through the D and G band Raman peaks, the reduction of GO to RGO was confirmed. The optical properties of the prepared material were analyzed using UV‐visible spectroscopy and photoluminescence analysis, respectively. The carrier lifetime of the TiO2 and TiO2/RGO composites was studied using time resolved photoluminescence studies. The high‐resolution transmission electron microscope images of prepared TiO2/RGO composites were found to have sheet‐like structure surrounding the near spherical nanoparticles, which could be attributed to that of RGO and TiO2, respectively. The binding energy states of the prepared material were studied using X‐ray photoelectron spectroscopy (XPS) spectra. The incorporation of RGO in TiO2 was found to improve the Brunauer–Emmett–Teller (BET) surface area of TiO2 and distribution of pores in TiO2 and TiO2/RGO composites was found to be uniform. The DSSCs were fabricated using the prepared TiO2 and TiO2/RGO composites as photoanodes and their power conversion efficiencies were analyzed.
Rajkumar Senthamarai, Venkatraman Madurai Ramakrishnan, Balraju Palanisamy, and Suguna Kulandhaivel
Hindawi Limited
Clean and green energy being worlds priority today, here in this work TiO2 nanostructures were prepared via green route using the fruit extracts derived from pineapple, orange, and grapes as reducing agents respectively. The anatase phase of the prepared TiO2 nanostructures was confirmed through the X‐ray diffraction pattern and the Raman analysis, respectively. Field emission scanning electron microscope (FESEM) images of the samples was found to exhibit nanorods like morphology. Further, the functional groups and the optical properties of the synthesized TiO2 and Murraya koenigii fruit dye were confirmed using Fourier‐transform infrared spectroscopy (FT‐IR) and UV‐Vis spectroscopy, respectively. From the Tauc plot, the indirect bandgap values of the TiO2 nanostructures were calculated. Using the prepared TiO2 nanostructures as photoanodes dye‐sensitized solar cells were fabricated and its performance was studied. In this work, two different dyes such as the natural extract derived from the fruit skin of Murraya koenigii and the commercial N719 dye were used as sensitizers.
Selvakumar Pitchaiya, Nandhakumar Eswaramoorthy, Muthukumarasamy Natarajan, Agilan Santhanam, Vijayshankar Asokan, Venkatraman Madurai Ramakrishnan, Balasundaraprabhu Rangasamy, Senthilarasu Sundaram, Punniamoorthy Ravirajan, and Dhayalan Velauthapillai
Springer Science and Business Media LLC
AbstractPerovskite solar cells (PSCs) composed of organic polymer-based hole-transporting materials (HTMs) are considered to be an important strategy in improving the device performance, to compete with conventional solar cells. Yet the use of such expensive and unstable HTMs, together with hygroscopic perovskite structure remains a concern – an arguable aspect for the prospect of onsite photovoltaic (PV) application. Herein, we have demonstrated the sustainable fabrication of efficient and air-stable PSCs composed of an invasive plant (Eichhornia crassipes) extracted porous graphitic carbon (EC-GC) which plays a dual role as HTM/counter electrode. The changes in annealing temperature (~450 °C, ~850 °C and ~1000 °C) while extracting the EC-GC, made a significant impact on the degree of graphitization - a remarkable criterion in determining the device performance. Hence, the fabricated champion device-1c: Glass/FTO/c-TiO2/mp-TiO2/CH3NH3PbI3−xClx/EC-GC10@CH3NH3PbI3−x Clx/EC-GC10) exhibited a PCE of 8.52%. Surprisingly, the introduced EC-GC10 encapsulated perovskite interfacial layer at the perovskite/HTM interface helps in overcoming the moisture degradation of the hygroscopic perovskite layer in which the same champion device-1c evinced better air stability retaining its efficiency ~94.40% for 1000 hours. We believe that this present work on invasive plant extracted carbon playing a dual role, together as an interfacial layer may pave the way towards a reliable perovskite photovoltaic device at low-cost.
Venkatraman Madurai Ramakrishnan, Selvakumar Pitchaiya, N. Muthukumarasamy, Kristin Kvamme, G. Rajesh, S. Agilan, Arivalagan Pugazhendhi, and Dhayalan Velauthapillai
Elsevier BV
Venkatraman Madurai Ramakrishnan, Muthukumarasamy N., Balraju P., Selvakumar Pitchaiya, Dhayalan Velauthapillai, and Arivalagan Pugazhendhi
Elsevier BV
Selvakumar Pitchaiya, Muthukumarasamy Natarajan, Agilan Santhanam, Vijayshankar Asokan, Akila Yuvapragasam, Venkatraman Madurai Ramakrishnan, Subramaniam E. Palanisamy, Senthilarasu Sundaram, and Dhayalan Velauthapillai
Elsevier BV
Venkatraman Madurai Ramakrishnan, Sondre Sandberg, N. Muthukumarasamy, Kristin Kvamme, P. Balraju, S. Agilan, and Dhayalan Velauthapillai
Elsevier BV
Selvakumar Pitchaiya, Muthukumarasamy Natarajan, Agilan Santhanam, Vijayshankar Asokan, Venkatraman Madurai Ramakrishnan, Yuvaraj Selvaraj, Akila Yuvapragasam, Balasundaraprabhu Rangasamy, Senthilarasu Sundaram, and Dhayalan Velauthapillai
Elsevier BV
G. Balaji, R. Balasundaraprabhu, S. Prasanna, N. Prabavathy, M.R. Venkatraman, Vijayshankar Asokan, N. Muthukumarasamy, M.D. Kannan, and K. Sivakumaran
Elsevier BV
Selvakumar Pitchaiya, Muthukumarasamy Natarajan, Agilan Santhanam, Venkatraman Madurai Ramakrishnan, Vijayshankar Asokan, Pavithrakumar Palanichamy, Balasundaraprabhu Rangasamy, Senthilarasu Sundaram, and Dhayalan Velauthapillai
Elsevier BV
Venkatraman Madurai Ramakrishnan, Muthukumarasamy Natarajan, Agilan Santhanam, Vijayshankar Asokan, and Dhayalan Velauthapillai
Elsevier BV
D. Vinoth Pandi, N. Muthukumarasamy, S. Agilan, M. R. Venkat Raman, Y. Akila, and Dhayalan Velauthapillai
Springer Science and Business Media LLC
P.M. Ponnusamy, S. Agilan, N. Muthukumarasamy, T.S. Senthil, G. Rajesh, M.R. Venkatraman, and Dhayalan Velauthapillai
Elsevier BV