Fully transparent flexible 2D molybdenum disulfide transistors

Transparent flexible field-effect transistors (FETs) are increasingly desired for cutting-edge electronics. However, the performance of flexible two-dimensional (2D) FETs still lag behind traditional rigid 2D devices, which is largely associated with the electrode contact and manufacture process involved. Organic conductive polymers, such as poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), are promising electrode candidates due to their solution processability, tunable work function, transparency, and mechanical flexibility. Here, we introduce the lithographically defined PEDOT:PSS electrodes to fabricate the high-performance 2D transistors with excellent electrode/2D contact via a transfer method. Both flexible MoS2 FET and its rigid counterpart, employing PEDOT:PSS electrode, have demonstrated the impressive electron mobility values of 158 ± 26.7 cm2 V-1 s-1 and 155 ± 15.9 cm2 V-1 s-1, respectively. The PEDOT:PSS/MoS2 interface interaction has been meticulously characterized and computationally analyzed to elucidate the operational mechanisms. A fully transparent flexible 2D transistor, with 71% transmittance over the visible spectrum and robust FET performance under mechanical bending, is also demonstrated. Our work highlights the significant potential of integrating organic polymer electrodes with advanced 2D materials for novel high-performance device applications.