First-principles study on the piezoresistive effect of Ge/Si core/shell Nanowires

• Main Authors: Lei Li, Shuang-Ying Lei, Hong Yu, Qing-An Huang
• Format: Conference Proceeding
• Language: English
• Subjects: Atomic layer deposition; Conductivity; Effective mass; Nanowires; Piezoresistance; Silicon; Strain
• ISSN: 1930-0395; 2168-9229
• DOI: 10.1109/ICSENS.2012.6411348

We have simulated the piezoresistance coefficients (Pie Coefficients) in some certain Germanium nanowire (GeNW), Silicon nanowire (SiNW) and several Ge/Si core/shell nanowires based on the first-principles calculations. All the nanowires are with a same diameter in ; direction and remain unsaturated on surface. In these ; nanowires, It was found that the Pie Coefficients of the SiNW and the Ge 1 Si 3 (Ge/Si core/shell nanowire with three layers of silicon atoms) can reach as much as 35.26 × 10 -11 Pa -1 and 30.0 × 10 -11 Pa -1 under 2.5% tension in the longitudinal direction. And all those of the GeNW and the Ge 3 Si 1 (with only one silicon atom layer) almost kept negative values from -1 × 10 -11 Pa -1 to -9 × 10 -11 Pa -1 , whether under compressions or tensions. However, under compressions, the Ge 2 Si 2 (with two layers of silicon atoms surrounded outside) almost had no piezoresistive effect.