Persistent photoconductivity in micro-structured 2D-Mo1-xWxS2 alloys

We report a facile route to simultaneously enhance the photoresponse and persistent photoconductivity of laser-synthesized transition metal dichalcogenides (2D-TMDs) via synergic effects of micro-structuring and alloying. The photocurrent of 2D-Mo 1-x W x S 2 alloy photoconductors and its dynamics are studied under optical excitation within the visible spectral region. These devices feature periodic thickness variation resulting from spontaneously formed laser-induced periodic surface structures (LIPSS) in comparison with corresponding devices that utilize continuous films with the same compositions. We show that in micro-structured 2D-TMD alloy devices, the overall photocurrent is higher in amplitude by almost two orders of magnitude for some compositions, as compared to their “continuous” counterparts of the same composition. Most importantly, the persistent photoconductivity is strongly influenced by both surface micro-structuring and composition. • Direct laser synthesis of surface microstructured TMD alloys • Defect engineering by laser-microstructuring and alloying of laser-printed 2D-TMDs • Alloying and laser microstructuring adjusts persistent photoconductivity in 2D-TMDs