Fabrication of Bi2Te3 and Bi0.3Sb1.7Te3 thin films and devices on glass substrates by pulsed laser deposition

Bi-Te based thermoelectric thin films were fabricated by pulsed laser deposition (PLD). The effects of the substrate temperature on the thermoelectric properties of these films were studied to determine the optimal substrate temperature. A PLD technique in an argon atmosphere was developed for precise composition control of such films. Though the detailed mechanism of the effects of argon gas remains unclear, the thermoelectric properties of Bi-Te films on quartz glass substrates fabricated using our PLD method compared favorably with those of the bulk Bi-Te materials. The PLD-fabricated films were c-axis oriented to the surface of the substrates even though the substrates were quartz glass. This orientation might be due to the large anisotropic structure of Bi-Te compounds and might be favorable for optimizing in-plane thermoelectric properties. Finally, thermoelectric devices using c-axis oriented Bi₂Te₃ and Bi_0.3Sb_1.7Te₃ films on glass substrates were fabricated, and successfully generated electric power.