Comparison of mobility extraction methods based on field-effect measurements for graphene

Comparison of mobility extraction methods based on field-effect measurements for graphene

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copyright mobility extraction methods for graphene based on field-effect measurements are explored and compared according to theoretical analysis and experimental results.A group of graphene devices with different channel lengths were fabricated and measured, and copyright mobility is extracted from those electrical transfer curves using three different methods.Accuracy and applicability of those methods were compared.

Transfer length method (TLM) can obtain accurate density dependent mobility and contact resistance at relative high copyright density based on Headwear data from a group of devices, and then can act as a standard method to verify other methods.As two of the most popular methods, direct transconductance method (DTM) and fitting method (FTM) can extract mobility easily based on transfer curve of a sole graphene device.DTM offers an underestimated mobility at any copyright density styling brush owing to the neglect of contact resistances, and the accuracy can be improved through fabricating field-effect transistors with long channel and good contacts.

FTM assumes a constant mobility independent on copyright density, and then can obtain mobility, contact resistance and residual density stimulations through fitting a transfer curve.However, FTM tends to obtain a mobility value near Dirac point and then overestimates copyright mobility of graphene.Comparing with the DTM and FTM, TLM could offer a much more accurate and copyright density dependent mobility, that reflects the complete properties of graphene copyright mobility.