Thermoelectric performance of Cu intercalated layered TiSe2 above 300 K

High temperature (300–650 K) thermoelectric performance of Cu intercalated CuxTiSe2 (x = 0−0.11) material has been investigated. Cu intercalation transforms the p-type TiSe2 to n-type CuxTiSe2 with significant Seebeck coefficient value saturating to ∼−90 μV/K (x ≥ 0.06) at 650 K. Spanning the entire range of CuxTiSe2 samples, very low thermal conductivity has been observed which is attributed to the layered growth structure and rattling effect of weakly bound Cu atoms in the van der Waals gaps of TiSe2 layers. Figure of merit (ZT) value of 0.1 and 0.15 is achieved for pure TiSe2 and Cu0.11TiSe2 samples, respectively, at 650 K. The 4-element thermoelectric generator fabricated using a combination of p-type TiSe2 and n-type Cu0.11TiSe2 is designed, which gives an output power of 0.64 mW at 650 K.