Polyaniline-Layered Rutile TiO₂ Nanorods as Alternative Photoanode in Dye-Sensitized Solar Cells

Abstract

In this paper, dye-sensitized solar cell (DSSC) performance of the less explored polymorph of TiO 2 , rutile, has been explored, and its performance has been modified with polyaniline (PANI) wrapping on the surface. For this purpose, highly crystalline rutile nanorods have been synthesized without any growth-directing substrates, employing a hydrothermal treatment. Further, to understand the phase composition and morphology, the synthesized nanorods and PANI-layered nanorods have been characterized through various physicochemical methods. The synthesized rods were implemented as photoanode material for DSSCs which exhibited a photoelectric conversion efficiency (PCE) of 4.28% with a high open-circuit voltage ( V OC ) of 0.84 V which is highly superior to DSSC with Degussa P25 (PCE = 3.95%) TiO 2 nanoparticles. The resultant PCE of the nanorods was further enhanced to 6.23% on in situ deposition of PANI which acts as an electron-transporting layer. Introduction of conducting PANI over the rutile rod was explored as a new concept to improve the performance of photoanode material besides conventional TiCl 4 treatment or scattering layer deposition.

Design of Morphology-Controllable ZnO Nanorods/Nanopariticles Composite for Enhanced Performance of Dye-Sensitized Solar Cells

“…Besides, Kretzschmar et al observed that the electron lifetime in photoanode films fabricated with NRs was 2 times longer compared to that with nanoparticles [21]. Apart from efficient electron transport, 1-D nanostructures with tunable lengths ranging from hundreds of nanometers to micrometers are also promising light-scattering centers with enhanced optical propagation distance within the films and improved light collection efficiencies [22,23,24]. Nevertheless, excessive loss of accessible surface area and thus insufficient dye loading of these ZnO nanostructures limits their attainable photovoltaic efficiency to a relatively low level, making them less competitive in current DSCs embodiments.…”

A New Functional Composite for Photovoltaic and Sensor Applications

“…In order to evaluate the photovoltaic performance of the synthesized composite rods with the starting precursor TiO 2 and also a standard P25 TiO 2 sample, DSSC devices have been fabricated as per our previous methods. [ 11,27 ] The measured performance of the fabricated DSSC device is shown in Figure . The J–V characteristics of the DSSCs fabricated with synthesized CR, TP, and P25 are presented in Figure 7a.…”

“…[ 51,52 ] As evident from the microstructure analysis and the diffuse reflection spectra in Figure 6b, the slanting rods in the current case could favor adequate light scattering property and rapid electron transfer both could be responsible for the enhanced light harvesting to enhance the cell efficiency. [ 27,53,54 ] The particles, on the other hand, suffer from trapping/detrapping phenomenon in the conduction pathway between the grain boundaries, and therefore result in lesser efficiency than a rod. The enhanced photovoltaic performance of the composite may also arise from the band gap position of the mixture of phases.…”

“…The I–V characteristic study was carried by using an EKO MP‐160i I–V Tracer. [ 11,27 ] All the data represented are an average of measurements taken on five different devices for all the samples. EIS measurements were performed with an Autolab frequency analyzer setup equipped with an Autolab PGSTAT 10 and a frequency response analyzer module under solar simulator condition with the frequency range from 0.1 Hz to 100 kHz and at the 0.70 V open‐circuit voltage of the devices.…”

“…Recently, we have reported the performance of Gold (Au)‐decorated ZnO/TiO 2 as a stable photocatalyst and TiO 2 ‐polyaniline composite as a photoanode in DSSCs. [ 26,27 ] In addition, as a preliminary effort to eventually develop DSSC‐powered gas sensor, we have been exploring many oxide‐based systems to fabricate sensors that could exhibit response at room temperature for any analyte gas. As an outcome of our recent work in this endeavor, a composite nanorod (CR) of anatase TiO 2 with Na 0.23 TiO 2 has been found to exhibit both photovoltaic performance and gas sensing at room temperature as demonstrated in this work.…”