Properties of dinickel-silicides counter electrodes with rapid thermal annealing

Dinickel-silicide (Ni₂Si)/glass was employed as a counter electrode for a dye-sensitized solar cell (DSSC) device. Ni₂Si was formed by rapid thermal annealing (RTA) at 700°C for 15 seconds of a 50 nm-Ni/50 nm-Si/glass structure. For comparison, Ni₂Si on quartz was also prepared through conventional electric furnace annealing (CEA) at 800 °C for 30 minutes. XRD, XPS, and EDS line scanning of TEM were used to confirm the formation of Ni₂Si. TEM and CV were employed to confirm the microstructure and catalytic activity. Photovoltaic properties were examined using a solar simulator and potentiostat. XRD, XPS, and EDS line scanning results showed that both CEA and RTA successfully led to tne formation of nano thick- Ni₂Si phase. The catalytic activity of CEA-Ni₂Si and RTA-Ni₂Si with respect to Pt were 68 % and 56 %. Energy conversion efficiencies (ECEs) of DSSCs with CEA-Ni₂Si and RTA-Ni₂Si catalysts were 3.66 % and 3.16 %, respectively. Our results imply that nano-thick Ni₂Si may be used to replace Pt as a reduction catalytic layer for a DSSCs. Moreover, we show that nanothick Ni₂Si can be made available on a low-cost glass substrate via the RTA process