Improved Circuit Model Fitting of Inkjet-Printed OTFTs and a Proposal for Standardized Parameter Reporting

Within the field of organic thin-film transistors (OTFTs), a large variety of materials are available. As a consequence, it may not be possible for one circuit model to accurately replicate the behavior of all OTFT devices. We propose modifications to two popular circuit models in order to better match the characteristics observed in the devices manufactured using our materials system. Using measured data for complementary n- and p-type organic devices, modeling parameters are extracted through optimization. Due to the ubiquitous use of the square-law model to characterize organic devices, modeling parameters are also extracted using this traditional approach. Extracted parameters are then compared and discussed. As there is a clear variation in device parameters based on the model used, a new standardization scheme is proposed which attempts to provide a standardized quality assurance metric, which simplifies the comparison of the reported device parameters. This scheme provides an indication of the goodness of fit between the model being used to describe the device and the extracted modeling parameters.