Nanomechanical properties and fracture toughness of Bi3Se2Te thin films grown using pulsed laser deposition

作者：Phuoc Huu Le; Luo Chih Wei; Jian Sheng Rui^*; Lin Ting Chun; Yang Ping Feng

来源：Materials Chemistry and Physics, 2016, 182: 72-76.

DOI：10.1016/j.matchemphys.2016.07.006

• Thin films
• Nanoindentation
• Mechanical properties
• Fracture

Mechanical properties of thermoelectric (TE) materials are crucial for fabricating efficient and endurable TE devices. In this study, polycrystalline Bi3Se2Te thin films are grown on c-plane sapphire substrates at 250 degrees C and helium gas pressure of 6.5 x 10(-1) Torr using pulsed laser deposition (PLD). The structural, compositional, morphological and mechanical properties of Bi3Se2Te thin films are studied. The Bi3Se2Te thin films are highly c-axis oriented structure and exhibit the stoichiometric compositions of Bi3Se2Te phase. The hardness and Young's modulus of the Bi3Se2Te thin films are 5.6 +/- 0.2 GPa and 197.2 +/- 5.4 GPa, respectively, which determined by nanoindentation tests with the continuous stiffness measurement (CSM) mode. The true hardness of the Bi3Se2Te thin films is also calculated using the energy principle of nanoindentation contact. The micro-Vicker indentation-induced fracture behavior of the Bi3Se2Te thin films is observed and discussed.

• 出版日期2016-10-1