Improved performance in 0D/2D mixed dimensional homojunction MoS2 photodetectors by enhancing light absorption

Molybdenum disulfide (MoS2) possesses excellent potential for applications in the field of optoelectronic detection. However, the atomic-level thickness of the monolayer MoS2 leads to weak light absorption and a restricted absorption spectrum. The performance of monolayer MoS2 devices 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 MoS2 quantum dots (QDs) with high efficient light absorption with monolayer MoS2 to fabricate 0D/2D MoS2 QDs/MoS2 hybrid dimensional homojunction photodetectors. In this structure, MoS2 is used as an efficient carrier transport channel, while MoS2 QDs act as effective light absorbers to enhance the local electric field around MoS2. The synergistic effect of MoS2 QDs and MoS2 is utilized to accelerate the migration rate of photogenerated carriers in the structure, and in particular, the highest responsivity of the MoS2 QDs/MoS2 hybrid device is 27.6 A W−1 with the detectivity as high as 2.13 × 1011 Jones under 532 nm laser, which is an order of magnitude higher than that of the pristine MoS2 devices. The synergistic effect of MoS2 QDs with monolayer MoS2 is verified by finite-difference time-domain simulation. The results will pave the way for the future development of high-performance MoS2-based photodetectors.