Extraction of low-frequency noise in contact resistance of organic field-effect transistors

摘要

The power spectral density of low-frequency noise in contact resistance, S_(R_(sd)), of organic transistors is evaluated by the transfer-line method. The obtained gate-voltage dependent S_(R_(sd)) is then normalized by the square of contact resistance, which is extracted from dc current-voltage (Ⅰ-Ⅴ) measurements. After normalization, slightly variable and nearly constant S_(R_(sd)) /R_(sd)~2 with respect to gate voltage are obtained in the range 10~(-7)-10~(-6) μm/Hz at 20 Hz in p-type and n-type devices, respectively. This method proves suitable to investigate separately the origin of the noise sources in channel as well as in contact region.