Few-layer WSe2 lateral homo-and hetero-junctions with superior optoelectronic performance by laser manufacturing

Lateral hetero-junctions are considered as potential candidate for building blocks in modern electronics and optoelectronics,however,the construction of which remains a challenge.In this work,by using a laser-assisted manufacture technique,WSe2/WO3-x hetero-junction and monolayer/trilayer WSe2 homo-junction with Schottky diode like behavior are fabricated,both of which present competitive performance for photodetection and power generation in a wide range of wavelengths from ultraviolet to infrared,with maximum photoresponsivity of 10 A/W,external quantum efficiency of 14%,and power conversion efficiency of 1.3%.Combined with Kelvin probe microscopy and electrical transport measurements,it is demonstrated that the barrier-induced built-in electric field at WSe2/WO3-x interface,and the energy band discontinuities at the monolayer/trilayer WSe2 interface facilitate the separation of photo-generated electron-hole pairs.Our work provides a solid step towards the controllable construction of lateral junctions by laser-assisted manufacture for exploiting van der Waals materials-based novel electronic and optoelectronic applications.