Electrodeless thin film conductance measurements using the Sommer–Tanner method

A method to determine the electrical conductance of thin films such as a‐Si:H that does not require contacting electrodes is presented. This method, introduced by Sommer and Tanner, is based on measuring the phase shift of a capacitive transmission line. The lower detection limit for the geometry used here is 10−11 Ω−1, which makes it suitable to determine the photoconductivity of a‐Si:H thin films. The method shows reasonable agreement with classical conductance measurements using sputtered electrodes.