Bifacial dye-sensitized solar cells from transparent RuSe counter electrodes

Bifacial solar cells that can generate electricity from either front or rear side are regarded as advanced photovoltaics for markedly increased photoelectric conversion efficiency. We present here the fabrication of transparent RuSe counter electrodes by an alternating electrodeposition method for bifacial dye-sensitized solar cells (DSSCs). The catalytic and photovoltaics performances are maximized by tuning stoichiometric Ru/Se ratio and bilayer number. Upon irradiation by AM1.5 (100 mW cm−2), the device yields a maximized front efficiency of 8.72% and a rear efficiency of 5.9%, arising from the >80%-transparency of RuSe electrode in visible light region. This strategy provides new opportunities for fabricating high-performance DSSCs.