Stretchable Graphene: A Close Look at Fundamental Parameters through Biaxial Straining

• Published in: Nano letters 2010-09, Vol.10 (9), p.3453-3458
• Main Authors: Ding, Fei, Ji, Hengxing, Chen, Yonghai, Herklotz, Andreas, Dörr, Kathrin, Mei, Yongfeng, Rastelli, Armando, Schmidt, Oliver G
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Lattice dynamics; Materials science; Phonons in low-dimensional structures and small particles; Physics; Specific materials
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl101533x

Tunable biaxial stresses, both tensile and compressive, are applied to a single layer graphene by utilizing piezoelectric actuators. The Grüneisen parameters for the phonons responsible for the D, G, 2D and 2D′ peaks are studied. The results show that the D peak is composed of two peaks, unambiguously revealing that the 2D peak frequency (ω2D) is not exactly twice that of the D peak (ωD). This finding is confirmed by varying the biaxial strain of the graphene, from which we observe that the shift of ω2D/2 and ωD are different. The employed technique allows a detailed study of the interplay between the graphene geometrical structures and its electronic properties.