Nanoindentation of Bi2Se3 Thin Films

Abstract

The nanomechanical properties and nanoindentation responses of bismuth selenide (Bi2Se3) thin films are investigated in this study. The Bi2Se3 thin films are deposited on c-plane sapphire substrates using pulsed laser deposition. The microstructural properties of Bi2Se3 thin films are analyzed by means of X-ray diffraction (XRD). The XRD results indicated that Bi2Se3 thin films are exhibited the hexagonal crystal structure with a c-axis preferred growth orientation. Nanoindentation results showed the multiple “pop-ins” displayed in the loading segments of the load-displacement curves, suggesting that the deformation mechanisms in the hexagonal-structured Bi2Se3 films might have been governed by the nucleation and propagation of dislocations. Further, an energetic estimation of nanoindentation-induced dislocation associated with the observed pop-in effects was made using the classical dislocation theory.

Effects of Stoichiometry on Structural, Morphological and Nanomechanical Properties of Bi2Se3 Thin Films Deposited on InP(111) Substrates by Pulsed Laser Deposition

“…In general, better film crystallinity often results in superior nanomechanical properties [43,44]. Therefore, compared with those reported in [14], the larger values of hardness and Young's modulus of the present Bi2Se3 thin films could be attributed to their better crystallinity. Furthermore, the film surface roughness can also be an important factor.…”

“…In addition, Bi 2 Se 3 possesses excellent thermoelectric properties at room-temperature [9,10] and low temperature regimes [11]. For fundamental studies and application purposes, it is essential to grow Bi 2 Se 3 thin films with high-quality and to have comprehensive characterizations of their physical properties, including the mechanical properties [12][13][14].…”

Influence of Post-Annealing on the Structural and Nanomechanical Properties of Co Thin Films

“…For practical applications, since the manufacturing and packaging processes are inevitably involving contact loading, it is thus necessary to fully recognize the mechanical characteristics of Co thin films, especially in the nanoscale regime. To this respect, nanoindentation stands out as one of the most efficient tools for obtaining the basic mechanical characteristics, such as the hardness and elastic modulus, at small length scales of various thin films [7][8][9][10] or micro/nano-sized materials [11][12][13][14][15] owing to its advantages of high sensitivity, good resolution and easy operation. In addition, it has been widely recognized that the loading and unloading segments of the nanoindentation load-displacement curves often reflect rich information about the dominant deformation mechanism prevailing in the materials under investigation.…”

Annealing-Driven Microstructural Evolution and Its Effects on the Surface and Nanomechanical Properties of Cu-Doped NiO Thin Films

“…The changes in the film microstructure appeared to result in significant effects on the surface energy, in particular the wettability of the films as revealed by the X-ray photoelectron spectroscopy and the contact angle of the water droplets on the film surface. The nanoindentation tests further revealed that both the hardness and Young's modulus of the CNO thin films increased with the annealing temperature, suggesting that the strain state and/or grain boundaries may have played a prominent role in determining the film's nanomechanical characterizations.that the wide variety of methods used for fabricating NiO thin films often resulted in very different film microstructures or even stoichiometries.In this respect, nanoindentation has been widely used as a depth-sensing technique to measure fundamental mechanical properties such as the hardness, elastic modulus and the plasticity behaviors of various nanostructured materials [18][19][20][21] and thin films [22][23][24][25][26], due to its high sensitivity and excellent resolution. For instance, Fasaki et al [27] recently investigated the effects of substrate temperature (T s ) on the microstructure and nanomechanical properties of NiO thin films deposited on thermally oxidized Si substrates by using pulsed laser deposition.…”

“…In this respect, nanoindentation has been widely used as a depth-sensing technique to measure fundamental mechanical properties such as the hardness, elastic modulus and the plasticity behaviors of various nanostructured materials [18][19][20][21] and thin films [22][23][24][25][26], due to its high sensitivity and excellent resolution. For instance, Fasaki et al [27] recently investigated the effects of substrate temperature (T s ) on the microstructure and nanomechanical properties of NiO thin films deposited on thermally oxidized Si substrates by using pulsed laser deposition.…”