Simplified transient space-charge-limited current measurements of mobility using transimpedance amplifier

Transient space-charge-limited current measurement (also called time resolved dark injection) is a well known technique for mobility and contact ohmicity characterization in organic thin films. We demonstrate the feasibility of performing space-charge-limited transient current measurements using a transimpedance amplifier instead of the typically used bridge circuit. The use of a transimpedance amplifier significantly simplifies the experiment, particularly because it removes the requirements for bridge symmetry and per sample adjustment. Furthermore the experimental bandwidth and current sensitivity are increased. We detail the experiment design and verify the compatibility of measurements on a [6,6]-phenyl-C60-butyric acid methyl ester (60PCBM) blend thin film.

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► Fast and reliable mobility measurements in organic films based on current transients are achieved.
► A new solution based on the use of a transimpedance amplifier based circuit is developed.
► Its advantages compared to bridge based circuits is discussed and demonstrated with simulations.
► Mobility measurement in 60PCBM embedded in an insulating matrix of polytriarylamine (PTAA) is done for validation.