title: Reconstruction of Kelvin probe force microscopy image with experimentally calibrated point spread function.
abstract: A Kelvin probe force microscopy (KPFM) image is sometimes difficult to interpret because it is a blurred representation of the true surface potential (SP) distribution of the materials under test. The reason for the blurring is that KPFM relies on the detection of electrostatic force, which is a long-range force compared to other surface forces. Usually, KPFM imaging model is described as the convolution of the true SP distribution of the sample with an intrinsic point spread function (PSF) of the measurement system. To restore the true SP signals from the blurred ones, the intrinsic PSF of the system is needed. In this work, we present a way to experimentally calibrate the PSF of the KPFM system. Taking the actual probe shape and experimental parameters into consideration, this calibration method leads to a more accurate PSF than the ones obtained from simulations. Moreover, a nonlinear reconstruction algorithm based on total variation (TV) regularization is applied to KPFM measurement to reverse the blurring caused by PSF during KPFM imaging process; as a result, noises are reduced and the fidelity of SP signals is improved.
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Lan
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Minlin
authors.identifier: 0000000242856072
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Quan
authors.initials: Q
authors.lastname: Tao
authors.affiliation: School of Machine Engineering and Automation, Fuzhou University, Fujian 350116, China.
authors.forename: Fanan
authors.initials: F
authors.lastname: Wei
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Guangyong
authors.initials: G
authors.lastname: Li