http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/3 Tue, 07 Apr 2026 14:59:06 GMT 2026-04-07T14:59:06Z http://http://starc.stthomas.ac.in:8080/xmlui:8080/xmlui/bitstream/id/6bfe13a5-86df-41df-a432-811d8a85807c/ http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/3 http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/189 Multipodal formation of Tio2 nanotubes using anodization Naduvath, Johns; Bhargava, Parag; Mallick, Sudhanshu The titanium dioxide nanotube arrays with large pore size and multipodal nature have many applications including solar cells applications, three terminal devices, drug delivery and other light harvesting applications. A simple method for the formation of multipodal conical structures by anodization of Ti foil was introduced. During anodization of Ti foil using the electrolytes such as ethylene glycol, glycerol and diethylene glycol with higher water concentrations (from 10 vol% onwards), conical nanotubes of wider pore diameter ∼200nm were observed. In order to study the branching of nanotubes in detail, nanotubes with different morphologies were grown in different electrolyte compositions and influence of viscosity and conductivity of electrolyte on multipodal nanotube formation were studied. The mechanism for the formation of bigger conical nanotubes, which contain 3 to 4 nanotubes inside it, was not addressed properly. A detailed study of the formation of these unique nanostructures was performed and proposes a growth mechanism for the same. Fri, 22 Mar 2019 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/189 2019-03-22T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/127 Lead free, air stable perovskite derivative Cs2SnI6 as HTM in DSSCs employing TiO2 nanotubes as photoanode Peedikakkandy, Lekha; Naduvath, Johns; Mallick, Sudhanshu; Bhargava, Parag Cs2SnI6 is an air-stable and non-toxic perovskite variant photovoltaic material which exhibits p-type conductivity under doped conditions. In this work, we report the synthesis and stability studies of Cs2SnI6 towards its application as a solid-state Hole Transport Material (HTM) in Titania Nanotube (TNT) based Dye Sensitized Solar Cells (DSSCs). Cs2SnI6 crystals were synthesized using precipitation method and its stability was assessed using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Thermogravimetric Analysis (TGA). Cs2SnI6 doped with SnI2 was deposited onto the TNT photo-anode as the HTM layer through dip coating. Deposition time was varied to obtain a continuous layer of Cs2SnI6 HTM over TNT photo-anode and cell characteristics were studied. We were able to fabricate air stable, all solid-state solar cells with a Jsc of 6 mA/cm2, Voc of 536 mV and PCE of 1.3%. The study propounds contemporary analysis on Sn based perovskite systems, in the field of DSSCs. Sat, 01 Dec 2018 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/127 2018-12-01T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/125 A simple method to fabricate metal doped TiO2 nanotubes K, Aijo John; Naduvath, Johns; Remillard, Stephen K; Shaji, Sadasivan; DeYoung, Paul A; Kellner, Zachary T; Mallick, Sudhanshu; Thankamoniamma, Manju; Okram, Gunadhor S; Philip, Rachel Reena A simple electrochemical method for effective doping of TiO2 nanotubes with metals is presented here. The doping is done in a two-stage cost effective process and is found to result in uniform doping concentration, without any surface layer formation, in the nanotubes. Detailed structural, compositional, optical and electrical analyses are done on the nanotubes doped with copper metal. The cu metal doping is found to produce tuning of the electrical and optical properties. The doped tubes with increased conductivity are better suited in dye sensitized solar cells (dsscs) whereas enhanced visible light absorbing capacity makes them better candidates for photocatalytic applications. Further the success of this method in doping TiO2 nanotubes with any metal of choice is demonstrated by testing aluminum metal doping in the nanotubes. Mon, 01 Jul 2019 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/125 2019-07-01T00:00:00Z http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/120 Electrochemical Synthesis of Novel Zn-Doped TiO2 Nanotube/ZnO Nanoflake Heterostructure with Enhanced DSSC Efficiency K, Aijo John; Naduvath, Johns; Mallick, Sudhanshu; Pledger, Jacob W; Remillard, SK; DeYoung, PA; Thankamoniamma, Manju; Shripathi, T; Philip, Rachel Reena The paper reports the fabrication of Zn-doped TiO2 nanotubes (Zn-TONT)/ZnO nanoflakes heterostructure for the first time, which shows improved performance as a photoanode in dye-sensitized solar cell (DSSC). The layered structure of this novel nanoporous structure has been analyzed unambiguously by Rutherford backscattering spectroscopy, scanning electron microscopy, and X-ray diffractometer. The cell using the heterostructure as photoanode manifests an enhancement of about an order in the magnitude of the short circuit current and a seven-fold increase in efficiency, over pure TiO2 photoanodes. Characterizations further reveal that the Zn-TONT is preferentially oriented in [001] direction and there is a Ti metal-depleted interface layer which leads to better band alignment in DSSC. Sat, 02 Jul 2016 00:00:00 GMT http://starc.stthomas.ac.in:8080/xmlui/xmlui/handle/123456789/120 2016-07-02T00:00:00Z