Enhanced efficiency of PbS quantum dot-sensitized solar cells using plasmonic photoanode

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2018-07, Vol.20 (7), p.1-16, Article 198
• Main Authors: Bhardwaj, Swati, Pal, Arnab, Chatterjee, Kuntal, Rana, Tushar H, Bhattacharya, Gourav, Roy, Susanta Sinha, Chowdhury, Papia, Sharma, Ganesh D., Biswas, Subhayan
• Format: Article
• Language: English
• Subjects: Absorption; Absorption spectra; Characterization and Evaluation of Materials; Chemistry and Materials Science; Efficiency; Electrophoretic deposition; Energy conversion efficiency; Gold; Inorganic Chemistry; Lasers; Lead sulfides; Materials Science; Nanocomposites; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photoanodes; Photonics; Photovoltaic cells; Photovoltaics; Physical Chemistry; Quantum dots; Recombination; Research Paper; Solar cells; Spectroscopy; Spectrum analysis; Titanium dioxide; Transmission electron microscopy
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-018-4301-8

In this report, an effort has been made to develop an efficient PbS quantum dot-sensitized photoanode by simple successive ionic layer adsorption and reduction technique to enhance the overall photovoltaic performance of PbS quantum dot-sensitized solar cells. Three strategies have been adopted for the improvement of the photovoltaic performance of PbS quantum dot-sensitized solar cells, i.e., (i) by incorporation of TiO 2 -Au nanocomposites, where Au nanoparticles of different sizes are embedded into a TiO 2 matrix, and (ii) variation of temperature at which quantum dots are deposited (iii) by postdeposition annealing of QD-sensitized photoanode in Ar atmosphere. We have used electrophoretic deposition technique to develop the nanocomposite-doped photoanode. High-resolution transmission electron microscopy confirms that the Au particles dispersed in the TiO 2 matrix vary from 2 to 50 nm and PbS quantum dot size ranges 3.5–6 nm. The optical absorption of PbS quantum dot-sensitized TiO 2 -Au-incorporated photoanode is substantially enhanced as confirmed from the UV-visible absorption spectra measurements. The current-voltage characteristics of all the plasmonic quantum dot-sensitized solar cells under illumination (100 mW/cm 2 , AM 1.5) show significant improvement in power conversion efficiency using the abovementioned strategies. The maximum power conversion efficiency observed in PbS quantum dot-based quantum dot-sensitized solar cells is 7.0%. Electroimpedance spectroscopy has been utilized to understand the recombination kinetics in these solar cells.