On the Extraction of Charge Carrier Mobility in High‐Mobility Organic Transistors

Abstract

Transistor parameter extraction by the conventional transconductance method can lead to a mobility overestimate. Organic transistors undergoing major contact resistance experience a significant drop in mobility upon mild annealing. Before annealing, strong field-dependent contact resistance yields nonlinear transfer curves with locally high transconductances, resulting in a mobility overestimate. After annealing, a contact resistance below 200 Ω cm is achieved, which is stable over a wide V(G) range.

Simulation of charge transport in organic semiconductors: A time-dependent multiscale method based on nonequilibrium Green's functions

“…[35]. It should be noted, though, that although mobility is the figure of merit of molecular semiconductors commonly reported in the literature, in transistor measurements mobility is not an intrinsic materials property, rather it depends on several parameters such as the dielectric capacitance [36], the surface roughness [37], or even on the extraction method [38].…”

Electron Mobility Exceeding 10 cm2 V−1 s−1 and Band‐Like Charge Transport in Solution‐Processed n‐Channel Organic Thin‐Film Transistors

“…The low contact resistance observed here is similar to the reported contact resistance of the OTFTs of 2,9-didecyl-dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]-thiophene after annealing treatment, which also exhibited a mild decrease upon increasing gate voltage. [33] By examining the drain current with exclusion of the effect of contact resistance, we conclude that the contact resistance is a contributing but not a dominant factor leading to the nonideal behavior of transfer curves.…”

Charge carrier mobility in thin films of organic semiconductors by the gated van der Pauw method

“…Proper parameter extraction is complicated by the fact that carrier injection from the contact into the semiconductor is often mediated by the gate voltage V G . When this is not properly taken into account, it leads to serious over-estimation of the mobility141516. Therefore, a more accurate, yet simple, method is highly desirable for the proper evaluation of μ tfsc , the charge carrier mobility in thin films of organic semiconductors in the high-charge density accumulation layer.…”