Analyzing the polarization distribution in poled polymer films by scanning Kelvin microscopy

Abstract

We present a method for analyzing the homogeneity of the χ(2) distribution in poled nonlinear optical polymer films. The second-order nonlinear coefficient in these polymers is commonly induced by electric-field poling methods which can lead to a χ(2) distribution with poor spatial homogeneity. In this letter, we analyze the χ(2) distribution using scanning Kelvin microscopy. This allows us to detect the height and the direction of the induced polarization through the probing of the countercharges that are present on the polymer surface. We compare the response to that obtained from the scanning second-harmonic microscopy method, in which the direction of the orientation, and thus the phase of χ(2), cannot be seen.

Space charges in solid electrolytes detected by the scanning Kelvin probe

“…To this aim, besides pressure pulse and thermal methods the scanning Kelvin probe has been revived in the last years. This measurement technique was introduced by Lord Kelvin and further developed by Zisman as well as by many others [10][11][12][13][14][15][16][17][18]. The method allows to determine the work function difference of metals or the surface potential of insulators contactless.…”

Imaging of conductive filler networks in heterogeneous materials by scanning Kelvin microscopy

“…The vibrating capacitor or Kelvin1, 2 method is a well‐established experimental technique for measuring the contact potential difference (CPD) or the work function of metal3 and semiconductor surfaces 4, 5. In addition, the method can be applied to other classes of materials such as polymers6 and carbon black (CB) 7. Here, the sensitivity of the CPD to the appearance of electronic surface states and surface charges is used.…”