Research On Mid-Infrared Light Source And Photodetector Based On Black Phosphorus

With the continuous advancement of science and technology,we are no longer satisfied with the traditional combination and integration of photonic devices and optoelectronic devices.Traditional optoelectronic devices are large in size,high in power consumption,and difficult to maintain.The advent of transistors has made integrated circuits in accordance develop with Moore’s Law.Our need for miniaturized and integrated devices is also increasingly urgent.Due to a series of difficult problems brought about by further reducing the size of transistor cells,such as:short channel effect,off-state energy consumption,etc.,the performance improvement of microelectronic chips using electrons as information carriers has encountered a huge bottleneck.Since graphene was successfully exfoliated in 2004,two-dimensional（2D）materials have attracted extensive research enthusiasm among academic scientists due to their unique and excellent physical and chemical properties.Among them,black phosphorus（BP）has excellent properties such as direct band gap adjustable with the number of layers,high carrier mobility and unique anisotropy,and has the characteristics of the band gap in the infrared band,making it has broad application prospects in the fields of electronics and optoelectronics.In view of this,this paper uses a self-built infrared fluorescence spectroscopy test system to explore a series of properties of the 2D infrared material BP.Starting from basic Raman and fluorescence spectroscopy,to prepare related devices,including BP-based mid-infrared（MIR）microcavities,waveguide-coupled radiation structures combined with zinc oxide（Zn O）nanowires,and perovskite combination carrier transport device.These explorations provide a basis for the future development of MIR photonic integration and photodetectors.The main innovative achievements and significance are summarized as follows:（1）Based on the direct bandgap characteristics dependent on the BP layers,the basic properties of BP were systematically explored,including the related research on factors such as thickness,temperature and bandgap,which laid a certain experimental foundation for the further exploration of the subsequent performance and devices of BP.By comparing the contrast of BP with different thicknesses on the silicon substrate with285 nm silicon oxide grown on the surface,a quick method for judging the thickness of BP is summarized and provided.By testing the fluorescence spectra of BP with different thicknesses,the dependence of the thickness of BP on the band gap is summarized,which provides some experimental evidence for theoretical calculation.By testing the fluorescence signals of BP at different temperatures,the relationship between the peak position and intensity of BP with temperature changes under the condition of variable temperature was found and explained.These works expand the application of BP in the MIR band,and lay a foundation for subsequent device applications and optoelectronic properties research.（2）With the help of BP and distributed Bragg reflection（DBR）microcavity structure,there is strong light-matter interaction with the light source,a BP nanosheet-based stable long temperature region and wavelength tunable MIR laser can be successfully prepared.The polarization tests in the case of amplified spontaneous emission and lasing have experimentally confirmed the occurrence of lasing behavior.This laser has a MIR tunable range up to 643 nm（the emission wavelength can be modulated from 3425 to 4068 nm）and temperature-independent emission stability（from77 K to 358 K）.The design of the cladding structure of the microcavity effectively overcomes the defect of easy oxidation of BP.The realization of BP-based wide-wavelength tunable MIR lasers broadens the application of 2D materials in future integrated photonic systems on silicon substrates.（3）Based on the elongated shape of BP nanoribbons and the one-dimensional structural characteristics of Zn O nanowires,a waveguide composite device structure of Zn O nanowires-BP nanoribbons was constructed,and a radiation-enhanced MIR light source of BP was successfully realized.This composite structure belongs to an application example of BP nanoribbon,and this discovery lays a foundation for the subsequent research on MIR on-chip signal generation and processing.Through a series of Raman and fluorescence polarization spectroscopy tests,a concise solution for judging the crystal orientation of BPnanoribbons is summarized and provided.Based on the wide-bandgap semiconductor Zn O waveguide design and the electric field-induced refractive index change effect,the coupling efficiency between Zn O nanowire and BP is greatly increased,which has important reference significance for the subsequent research on enhancing the interaction between light and matter.（4）Based on the two-dimensional properties of thin-layer BP,perovskite nanosheets（MAPb Br₃）were directly grown on two-dimensional BP nanosheets by anti-solvent method,and high-quality BP-perovskite heterojunction with tunable morphology was successfully prepared.This work provides a facile method to fabricate2D BP-MAPb Br₃ heterojunctions.Transient spectroscopy and optoelectronic properties tests confirmed the charge transfer process at the BP-MAPb Br3 heterojunction interface,and the optoelectronic devices based on this heterojunction exhibited a responsivity as high as 948.71 A/W.The preparation and optoelectronic properties of this structure provide a good basis for the subsequent development and preparation of 2D high-performance detectors,and promote the development of 2D-based detectors.