Atomic Force Microscope Based Kelvin Probe Measurements:  Application to an Electrochemical Reaction

Abstract

An atomic force microscope (AFM) was utilized as a Kelvin probe to determine work functions of several metals and semiconductors quantitarively. Most of the experimental data show excellent agreement with published values measured by photoemission. Variations in work functions as low as 5 mV could be detectcd with a typical lateral resolution of 20 nm. This method allowed us to analyze and explain thc energetics of an electrochemical reaction on the surface of WSe2, which could be in situ induced and con&olled by an externally applied voltage between AFM tip and sample. Thus it could be exploited for etchng nanosfructwes.

Ge2Sb2Te5 layer used as solid electrolyte in conductive-bridge memory devices fabricated on flexible substrate

“…In addition, since set and reset processes are electrode-dominated in the case of conductive-bridge devices [5], the difference in set/reset voltages may also originates from the different electronic properties, such as work function of the electrode material, where the ~800 mV difference observed between set voltages almost corresponds to the work function difference between W (4.55 eV) [28] and platinum-iridium (5.3 eV). [29] To summarize, these above-mentioned results demonstrate the feasibility of crossbar CBRAM memory elements fabricated on a flexible substrate by using heterogeneous elaboration processes combining conventional physical thin film deposition and inkjet-printing. Future measurements, including retention, cycling and robustness against mechanical stress (e.g.…”

Investigation of Kelvin probe force microscopy efficiency for the detection of hydrogen ingress by cathodic charging in an aluminium alloy

“…KFM is based on the vibrating capacitor method (Kelvin method) [1] adapted to an AFM probe. Since its first use for measuring the contact potential difference at the nanometer scale [2][3][4], this technique has been used to study electrochemical mechanisms [5] and localized corrosion [6][7][8][9]. Masuda [10] studied the stress corrosion cracking (SCC) of SUS304 stainless steel by KFM and attributed the surface potential variations to hydrogen produced by cathodic reactions.…”

Object size effect on the contact potential difference measured by scanning Kelvin probe method

“…In most works, authors compare SKPM results with either literature data or with data measured by photo-electron emission spectroscopy [8,[11][12][13].…”