Supplementary Material (clean, not marked-up)

Supplementary material includes (1) details of the experimental procedure for mapping current density; (2) an example that reassesses the fringe current correction attempt of our prior experimental work where velocity saturation was neglected; (3) closed-form expressions for the drain current and saturation voltage for a patterned-channel transistor; (4) the general formulation of the 2D current flow problem in an unpatterned-channel TFT; (5) a demonstration that the dimensionless parameters in Table 1 uniquely characterize the "shape" of the current distribution in an unpatterned TFT; (6) an exact derivation of the fringe current in an infinitely wide unpatterned TFT; (7) quantitative details of decay of current density away from the contacts.

本补充材料包含以下内容：(1) 电流密度映射实验流程的详细细节；(2) 一则复现案例：重新评估我们此前未考虑速度饱和效应的实验工作中所尝试的边缘电流校正方案；(3) 图案化沟道晶体管的漏极电流与饱和电压闭式表达式；(4) 非图案化沟道薄膜晶体管(thin-film transistor, TFT)的二维电流流动问题通用表述；(5) 证明表1中的无量纲参数可唯一表征非图案化TFT的电流分布“形态”；(6) 无限宽非图案化TFT中边缘电流的精确推导过程；(7) 电流密度从接触电极向外衰减的定量细节。