Improved performance in 0D/2D mixed dimensional homojunction MoS2photodetectors by enhancing light absorption.

Abstract

Molybdenum disulfide (MoS₂) possesses excellent potential for applications in the field of optoelectronic detection. However, the atomic-level thickness of the monolayer MoS₂leads to weak light absorption and a restricted absorption spectrum. The performance of monolayer MoS₂devices has reached a bottleneck. Fortunately, the above issues can be effectively solved by coupling with various types of photosensitivity nanostructures. In this work, we integrated MoS₂quantum dots (QDs) with high efficient light absorption with monolayer MoS₂to fabricate 0D/2D MoS₂QDs/MoS₂hybrid dimensional homojunction photodetectors. In this structure, MoS₂is used as an efficient carrier transport channel, while MoS₂QDs act as effective light absorbers to enhance the local electric field around MoS₂. The synergistic effect of MoS₂QDs and MoS₂is utilized to accelerate the migration rate of photogenerated carriers in the structure, and in particular, the highest responsivity of the MoS₂QDs/MoS₂hybrid device is 27.6 A W^-1with the detectivity as high as 2.13 × 10¹¹Jones under 532 nm laser, which is an order of magnitude higher than that of the pristine MoS₂devices. The synergistic effect of MoS₂QDs with monolayer MoS₂is verified by finite-difference time-domain simulation. The results will pave the way for the future development of high-performance MoS₂-based photodetectors.