Plasmon Enhanced Photodetection Of Vertically Stacked Nanostructure Based On Inorganic Perovskite

Inorganic metal halide perovskites CsPb X₃(X=Cl,Br,I)are extensively concerned in light emitting diodes,solar cells and photodetectors due to low cost,facile synthesis and excellent scalability.However,the narrow optical absorption,low optical response and poor stretchability of CsPb X₃ still hinder their application in large scale,high performance and wearable optoelectronic devices.Therefore,it is urgent to seek a desirable way to address these challenges.In this work,inorganic perovskite-based vertically stacked multilayer architectures were designed and fabricated.The architectures address the challenges of perovskite,harness synergy effect of multilayer,which provide a new strategy for enhancing performance of inorganic perovskite-based optoelectronic devices.Taking photodetector as an example,we investigated the photoelectric characteristics of inorganic perovskite-based vertically stacked multilayer architectures and its application in functional optoelectronic devices.The key points are summarized as follows:1.Vertically stacked gold nanoparticles/lead sulfide quantum dots/perovskite nanoplatelets(Au/PbS/CsPbCl₃)phototransistors were fabricated by a simple low-temperature solution method.The vertically stacked Au/PbS/CsPbCl₃ architecture combines strong optical absorption of Au surface plasmon,the broadband optical absorption of PbS quantum dots,and the high carrier mobility of CsPbCl₃ nanoplatelets.Therefore,the architecture not only addresses the issues of poor optical response and narrow optical absorption range of perovskite,but also overcomes the shortcomings of low carrier mobility and small absorption cross-section of PbS.Moreover,the interface between vertically stacked layers can make carriers separation more effectively,and the plasmonic near-field of gold nanoparticles is coupled to optical absorption process of PbS/CsPbCl₃,which can also significantly enhance the effective optical absorption of photoactive layer.The results indicate that the phototransistors based on vertically stacked Au/PbS/CsPbCl₃ architecture not only exhibited ability of ultraviolet-visible-near infrared wide spectrum photodetection,but also demonstrated an optical responsivity as high as 3892 A/W,a high detectivity of 3.29×10¹³ Jones and an ultrahigh external quantum efficiency of 10⁶%.2.Vertically stacked poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/lead sulfide quantum dots/perovskite nanoplatelets(PEDOT:PSS/PbS/CsPbCl₃)phototransistors were fabricated by a simple low-temperature solution method.PEDOT:PSS/PbS/CsPbCl₃phototransistors can work at low voltage due to their high effective carrier mobility(41.26 cm²/V s),which make them have potential applications in low power consumption optoelectronic devices.PEDOT:PSS/PbS/CsPbCl₃phototransistors demonstrated a signal-to-noise ratios as high as 10² under the illumination of red,green and purple light sources.Compared with PbS or CsPbCl₃phototransistors,the photodetection performances of PEDOT:PSS/PbS/CsPbCl₃phototransistors are enhanced significantly,the responsivity and detectivity are 147.35A/W and 6.77×10¹² Jones,respectively.3.Flexible photodetectors were fabricated by a simple low-temperature solution method based on vertically stacked PEDOT:PSS/PbS/CsPbCl₃ architecture.The architecture combines high conductivity and strong adhesion of PEDOT:PSS,broadband optical absorption of PbS as well as high carrier mobility of CsPbCl₃.The results indicate that PEDOT:PSS/PbS/CsPbCl₃ flexible photodetector can work normally at a low voltage of 0.6 V,and photocurrent are stable after a bending angle of180°or 1000 times of bending.It is indicated that although there are drifts for photocurrent,there is no obvious device performance degradation after several bending.Under the illumination of red,green and purple light sources,the flexible PEDOT:PSS/PbS/CsPbCl₃ photodetectors demonstrated excellent photodetection performances.Their responsivity and detectivity are 6.67 A/W and 5.78×10¹⁰ Jones,respectively.In summary,the inorganic perovskite based vertically stacked multilayer architectures were designed and fabricated in this work.The architectures address the issues of low optical response,narrow optical absorption range and poor stretchability of inorganic perovskite,paving the way for the application of inorganic perovskite in future optoelectronic devices.