title: An improved AFM cross-sectional method for piezoelectric nanostructures properties investigation: application to GaN nanowires.
abstract: We present an improved atomic force microscopy (AFM) method to study the piezoelectric properties of nanostructures. An AFM tip is used to deform a free-standing piezoelectric nanowire. The deflection of the nanowire induces an electric potential via the piezoelectric effect, which is measured by the AFM coating tip. During the manipulation, the applied force, the forcing location and the nanowire's deflection are precisely known and under strict control. We show the measurements carried out on intrinsic GaN and n-doped GaN-AlN-GaN nanowires by using our method. The measured electric potential, as high as 200 mV for n-doped GaN-AlN-GaN nanowire and 150 mV for intrinsic GaN nanowire, have been obtained, these values are higher than theoretical calculations. Our investigation method is exceptionally useful to thoroughly examine and completely understand the piezoelectric phenomena of nanostructures. Our experimental observations intuitively reveal the great potential of piezoelectric nanostructures for converting mechanical energy into electricity. The piezoelectric properties of nanostructures, which are demonstrated in detail in this paper, represent a promising approach to fabricating cost-effective nano-generators and highly sensitive self-powered NEMS sensors.
authors.affiliation: IMEP-LAHC, Grenoble Institute of Technology, MINATEC, BP 257, 3 parvis Louis NEEL 38016 Grenoble, France. xu.xin.letterbox@gmail.com
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Alexis
authors.initials: A
authors.lastname: Potié
authors.forename: Rudeesun
authors.initials: R
authors.lastname: Songmuang
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Lee
authors.forename: Bogdan
authors.initials: B
authors.lastname: Bercu
authors.forename: Thierry
authors.initials: T
authors.lastname: Baron
authors.forename: Bassem
authors.initials: B
authors.lastname: Salem
authors.forename: Laurent
authors.initials: L
authors.lastname: Montès