CdS sensitized TiO2 nanorod arrays based solar cells prepared with polymer-assisted layer-by-layer adsorption and reaction method

High performance CdS sensitized TiO2 nanorod arrays based solar cells are fabricated by polymer-assisted layer-by-layer adsorption and reaction (PA-LBLAR) method. The PA-LBLAR method can well control the deposited size of CdS on the TiO2 nanorod arrays, which are grown on Ti foils by hydrothermal route then transferred to transparent conductive glasses. The UV-vis absorption spectra show that with the increasing deposition times, the absorption spectra of photoelectrodes increased to a broader wavelength range, which is originated by the better coverage and increased size of CdS quantum dots on the TiO2 nanorod arrays as detected by SEM and TEM images. The highest power conversion efficiency of the cells (AM 1.5 G, 100 mWcm−2) up to 2.944% can be obtained with 7 cycles of PA-LBLAR deposition of CdS sensitized layers in the photoelectrodes, which is much higher than that of the best performance of cell with 14 cycles of traditional successive ionic layer adsorption and reaction processes.