Bi_2Te_3 thin films and GeTe/B_2Te_3 superlattices of different thicknesses are prepared on the silicon dioxide substrates by magnetron sputtering technique and thermally annealed at 573 K for 30 min. Thermoelectric(TE)measurements indicate that optimal thickness and thickness ratio improve the TE performance of Bi_2Te_3 thin films and GeTe/B_2Te_3 superlattices, respectively. High TE performances with figure-of-merit(ZT) values as high as 1.32 and 1.56 are achieved at 443 K for 30 nm and 50 nm Bi_2Te_3 thin films, respectively. These ZT values are higher than those of p-type Bi_2Te_3 alloys as reported. Relatively high ZT of the GeTe/B_2Te_3 superlattices at 300-380 K were 0.62-0.76. The achieved high ZT value may be attributed to the unique nano-and microstructures of the films,which increase phonon scattering and reduce thermal conductivity. The results indicate that Bi_2Te_3-based thin films can serve as high-performance materials for applications in TE devices. Bi 2 Te 3 thin films and GeTe / B 2 Te 3 superlattices of different thicknesses are prepared on the silicon dioxide substrate by magnetron sputtering technique and thermally annealed at 573 K for 30 min. Thermoelectric (TE) measurements indicate that the optimal thickness and thickness ratio improve the TE performance of Bi 2 Te 3 thin films and GeTe / B_2Te_3 superlattices, respectively. High TE performances with figure-of-merit (ZT) values ​​as high as 1.32 and 1.56 are achieved at 443 K for 30 nm and 50 nm Bi_2Te_3 thin films, respectively. These ZT values ​​are Higher than those of p-type Bi 2 Te 3 alloys as reported. Relatively high ZT of the GeTe / B 2 Te 3 superlattices at 300-380 K were 0.62-0.76. The achieved high ZT value may be attributed to the unique nano- and microstructures of the films, which increase phonon scattering and reduce thermal conductivity. The results indicate that Bi_2Te_3-based thin films can serve as high-performance materials for applications in TE devices.