Fabrication and Characterization of Printed Phototransistors Based on Monochalcogenide Inks

Two-dimensional (2D) layered semiconductors of Group-III monochalcogenides have gained increasing attention in photonics and electronics. The fabrication of large-scale, inexpensive inks which can be used in printed electronics applications is facilitated by the solution processing of 2D materials. In this study, gallium sulfide (GaS)-, gallium selenide (GaSe)-, and gallium telluride (GaTe)-loaded inks were synthesized and implemented to fabricate phototransistors on SiO 2 \Si substrates. To explore the printed device performances, several color illuminations were applied to the printed phototransistor, and the mobility, photoresponsivity, and external quantum efficiency parameters were compared. Under red-light illumination, the mobility of a GaTe nanoparticle-based phototransistor reached 7.456 cm 2 V –1 s –1 . The responsivity of the GaTe-based phototransistor was found to be the highest, with the value of 9.52 A W –1 under green light illumination. However, GaSe-based phototransistors gave the highest EQE value of 2482 (%) under blue light illumination with the mobility of 7.04 cm 2 V –1 s –1 . This study demonstrates that printable Group-III monochalcogenide inks can be synthesized with desired properties for use in printed electronic applications.