Inseparability between charge-injection barrier and out-of-plane mobility in staggered thin-film transistors

Contact resistance significantly affects the performance of thin-film transistors (TFTs), while its diverse material, structural, and mechanistic origins are yet to be fully conceptualized. This Letter sheds light on the inseparability between charge-injection barrier and out-of-plane mobility inherent to the contact resistance in staggered TFTs, an often-overlooked aspect that could lead to misinterpretation of many experimental data. By combining current–voltage measurement, drift-diffusion simulations, and photoemission spectroscopy on fabricated TFTs, we demonstrate procedures and results to individually assess these two closely interacting parameters, providing guidelines for more robust analysis and engineering of TFTs.