Current density enhancement for quantum dot-sensitized solar cells by modulation on the quantum dot loading amount of anatase nanowire array photoelectrodes

A second spin-coating process was employed for CuInS 2 quantum dot (QD)-sensitized TiO 2 nanowire-based solar cells, which is anticipated to increase the QD loading amount of photoelectrodes. And the photoelectrodes had been modulated by the quantum dot dispersion concentration and spin-coating cycles. The optical absorption spectra and photoluminescence spectra of different photoelectrodes were investigated, which had exhibited the larger QD loading amount and better charge separation property of photoelectrodes after the second spin-coating process. Meanwhile, a net connection structure had been formed between each nanowire by the suitable QD loading amount of the photoelectrodes, which had simultaneously provided more paths for charge transfer of the solar cells. By optimization, the CuInS 2 QD-sensitized TiO 2 nanowire solar cells prepared from QD dispersion concentration of 30 mg∙mL −1 and two spin-coating cycles had exhibited higher current density value, which had enhanced the photovoltaic conversion efficiency from 3.9 to 5.03%.