Unlocking Superior Photodetection Properties of Electrodeposited MoS₂ Quantum Dots

Quantum dots (QDs) based on transition metal dichalcogenides such as MoS₂ offer an alternative strategy to yield excellent optoelectronic properties and promote their photodetection performances. By synthesizing MoS₂ QDs through a controlled electrodeposition process, their superior photodetection properties are unlocked, surpassing those reported in existing literature. Through comprehensive characterization and analysis, the successful fabrication of MoS₂ QDs made of a mixture of metallic 1T-MoS₂ and semiconductor 1T/2H-MoS₂ is demonstrated. The photodetection response of MoS₂ QDs samples shows a synergistic effect between the two nuances of MoS₂, achieving under a standard solar simulator, 758 A W^-1 and 5.2·10¹³ Jones for the responsivity and the detectivity. Surprisingly, under UV excitation at 5 V bias for smaller MoS₂ QDs, the device demonstrates impressive responsivity and detectivity reaching up to 1708.7 A W^-1 and 1.2·10¹⁴ Jones, respectively as well as excellent external and internal quantum efficiencies of 5.4·10⁵% and 7.8·10⁵% establishing it as one of the highest-performing MoS₂-based photodetectors reported so far. This research not only sheds light on the potential of MoS₂ QDs but also paves the way for their integration into photodetection technologies with unprecedented sensitivity.