Research Of Black Phosphorus Photodetectors Based On Heterogeneous Integration

Black phosphorus exhibits excellent application potential in the fields of electronics and optoelectronics due to its unique anisotropic two-dimensional layered structure.In this diss'ertation,we systematicaliy researched photodetector based on black phosphorus,including the intrinsic photoelectric properties of black phosphorus,and the black phosphorus-metal nanostructured polarized photodetector based on localized plasma enhancement.By using the advantages of energy band structure of black phosphorus-molybdenum disulfide heterojunction we prepared high perfomance photodetector.In this dissertation,the photoresponse intensity,polarization sensitivity,and photoresponse time of this series of black phosphorus-based photodetectors were systematically measured and analyzed at room temperature.The main results are summarized as follows:(1)BP is a good two-dimensional optoelectronic semiconductor material,coupled with its anisotropic microstructure which make it has a certain sensitivity to polarized light.Therefore,this paper focuses on the photodetector with black phosphorus as the channel layer.The photoelectron characteristics of the photodetector with different powers and different angles of polarized light are studied in detail.It was found that the maximum photoresponsivity of the device is approximately 22A·W-1;The result illustrated that the photocurrent is 165nA at 90°incident light,which is twice time of the value at 0°;The photo-response time is?1.6ms.(2)We realized hetero integriation of BP and various metal nanostructure by electron beam exposure.The main machismcan be explained that we enhance BP photodetector performance and modulate the photoresposivity and polarized light sensitivity of BP photodector through the enhancement of metal nanostructure LSPR effective.The experiment results shows that the width,interval,200nm,and 300nm,and the 20nm gold nanoarrays have the lowest reflectivity rate for the wavelength between 400nm and 500nm.Based on this conclusion,we prepared a black phosphor/gold nanoarray black phosphor photodetector.Under the illumination of 457 nm wavelength incident light,the response of the photodetector to different angles polarized light is obviously changed,and the the maximum angle photoresponse current responseo is 7 times morethan the smallest angle;The light response time is 1.6ms.(3)Using a physical transfer method,a p-type black phosphorus/n-type molybdenum disulfide heterojunction photodetector was developed.Black phosphorus/molybdenum disulfide pn junction photodetector,when the heterojunction applied reverse bias voltage,the photocurrent is 11.5 times than dark current,which can detect weak light signal of a weak light signal with a light mW photo intensityi;When the heterojunction is pressured positive bias voltage,the maximum photoresponse current reached 9.89 microampere,and the photoresponsivity reached 30.9 A.W-1.The results of this study indicate that the black phosphorus/molybdenum disulfide p-n junction photodetector can not only achieve the detection of weak light signals but also satisfy the requirement of high photorespomsivity..