Optimization of cuscn solution casting for high stability all-solid-state dye-sensitized solar cell

Abstract

The conductivity of inorganic hole-conducting media α-CuSCN was improved by Ni(SCN)2 doping and mixing with α-CuSCN. The better pore-filling of CuSCN into TiO 2 was realized by triethylammonium hydrothiocycanate additive. The additive can suppress the crystallization of CuSCN and reduce its crystallite size. A significant improvement in short-circuit current is observed by CuSCN with reduced grain size and enhanced conductivity. All-solid-state dye-sensitized solar cells show a good stability in cell performance: for a sealed cell with 5 μm thick TiO 2 layer a short-circuit current enhancement is observed from 17 days to 46 days after assembly. Light soaking can further enhance the efficiency: the photovoltaic performance of the nanoparticular cell on day 17 increased up to a plateau value of = 2-12% (Voc = 0-5 V, Jsc = 7-1 mA/cm2, ff = 0.59) by 20 min illumination. To compare the performance of cells with different TiO 2 morphologies, titania nanotube array photo-electrodes were fabricated by anodizing a Ti foil and transferring the TiO 2 membrane onto FTO. In that case the best efficiency reached 2.1% was obtained for a freshly produced cell with a longer tube length (7 μm) due to faster charge transport and slower recombination rate. Copyright © 2012 American Scientific Publishers.