Study On The Photoelectric Detectors Based On Black Phosphorus Quantum Dot Materials

Quantum dots(QDs)materials have many excellent properties,such as intense light absorption,ultra-fast charge separation,and size control.Therefore,it has received extensive attention and application in the fields of low-cost and high-sensitivity photodetectors.The heterojunction structure formed by quantum dots and conductors or semiconductors has unique compatibility and excellent charge separation capability.It is a potential candidate for the development of high-performance next-generation optoelectronic devices.Highly responsive quantum dot photodetectors have been tested for broad spectrum of UV,Visible and Infrared.They have provided an opportunity for the integration of semiconductors and high performance devices.Black Phosphorus quantum dots(BPQDs)has high hole mobility and mature preparation technology.In the field of photonic and optoelectronic,they have been widely used to enhance the light gathering,photon conversion,photon absorption,etc.The photodetector based on BPQDs has not been widely reported,which limits its application in the field of photoelectric detection.In this paper,we studied the fabrication process of quantum dot-graphene fet,and designed the structure of organic-quantum dot doping and the compound structure of double quantum dots.We studied the optical and electrical properties of the prepared devices,and discussed their photocurrent transmission mechanism and device properties.They provide a new research direction for the application of BPQDs detector.In this paper,by using the method of wet transfer of single layer graphene,we prepared the quantum dot photodetector with transverse structure.Based on the theory of PN heterojunction,we selected the doped structure of P-type PC6iBM as electron acceptor and P-type black phosphorus quantum dot,and then we designed and prepared a horizontal PC61BM-BPQDs-Graphene photovoltaic detector.At the band of 450 nm-1000 nm,the response of the device reaches the order of 103 A/V.Compared with the PC61BM-Graphene detector,the response is improved by 2 orders of magnitude and the response time is obviously reduced.This device can achieve high response,fast detection and wide spectrum detection.Finally,we discussed the actors on the performance of this device,including the doped concentration of PC61BM and the size of electrodes.In this paper,we functionalized BPQDs with the lead sulfide quantum dots(PbS QDs).Based on effects of the photogating and the photoconductive gain,we designed and prepared a photoconductive detector with structures of the bottom gate and PbS QDs-BPQDs-Graphene.At the band of 400 nm-1000 nm,the response reaches the order of 103 A/W,the gain reaches the order of 106,and the external quantum efficiency reaches 2882%on this device.The device can achieve goals of high response,high gain and fast detection.Then,we proved that response is inversely proportional to power,the gain is directly proportional to power,and the external quantum eff-iciency is inversely proportional to power.Finally,we discussed the factors on the performance of this device,including graphene conductive channel,oxygen oxidation and the size of electrodes.