Non-precious transition metal-based counter electrodes for dye-sensitized solar cells

Abstract
A non-platinum metal catalyst, TiNx-C, was synthesized through the high-pressure pyrolysis method, which was characterized
using a transmission electron microscope, surface area measurement, X-ray photoelectron spectroscopy (XPS), and X-ray absorption fne structure (XAFS) studies. XPS analysis indicates the presence of Ti in 4+oxidation state, and XAFS meas�urement indicates the coordination number of Ti to be 4 and the Ti-N bond length to be 2.1 Å. Ti-C was used as reference
material. After fabricating dye-sensitized solar cell (DSSC), TiNx-C catalyst-based counter electrode (CE) exhibited com�parable electrical performance as Pt-based counter electrode. Replacing Pt with inexpensive TiNx-C is considered an efort
to lower the cost of the DSSC. In the DSSC, the TiNx-C CE showed comparable performance to Pt CE. Using TiNx-C as
CE, a FF of 0.58, η of 6% JSC of 14.4 mA cm−2, and VOC of 0.73 V were obtained. The Pt CE-based DSSC exhibited a FF
of 0.58, η of 7.2%, JSC of 16.0 mA cm−2, and VOC of 0.78 V