Investigation Of CsPbBr₃ Quantum Dots/Monolayer MoS₂ Hybrid Photodetector

Transition metal dichalcogenides?TMDs?have unique semiconductor physical properties and optical properties including direct band gap and high carrier mobility to meet the basic requirements of photodetectors.However,due to the atomic thickness in nature,the light-trapping ability of layered TMDs is very weak,which greatly limits the responsivity and detectivity of photodetectors,and thus inhibits the practical applications of such devices.Slow photoresponse rate is also a problem that often occurs in TMDs based devices.Thus,researchers have done a lot of research to improve the performance of TMDs based photodetectors.It is confirmed that the overall performance can be enhanced effectively by constructing TMDs based heterojunction with other materials.At present,lead-halide perovskite materials have been widely used in various types of optoelectronic devices,which has led to great research interests in hybrid devices of perovskite materials,especially in the field of solar cells and light emitting diodes.Recently,the perovskite/TMDs photodetectors display photoresponse performance and show good application prospects.In this paper,inorganic perovskite?CsPbBr₃?quantum dots are combined with monolayer molybdenum disulfide?MoS₂?to construct a 0D/2D hybrid photodetector.Here,the performance regulation of hybrid devices is achieved by changing the concentration and the content of surface organic ligands of perovskite quantum dots.In addition,we found that the oxygen adsorbate is beneficial to increase the response rate of the device and form p-type doping on the device,which reduces the number of electrons in the device to some extent.When the gate voltage is 0 V,the hybrid device exhibits high photoresponse performance,and the values of responsivity,external quantum efficiency,and specific detectivity ratio are6.40×10⁵ mA W^-1,1.50×10⁵%,and 3.38×10¹¹ Jones,respectively.Besides,the stability of as-synthesized all-inorganic perovskite quantum dots is confirmed after being irradiated by the of the continuous electron beam in TEM.The hybrid device also exhibits excellent working stability including high temperature endurance and work durability in air.