Design Of The Hot Electron Photodetector Based On Surface Plasmon

Hot electron photodetector is one of the effective ways to convert light energy into electricity,it is essentially a photoelectric converter and is one of the basic components of optoelectronic link.With the development of micro-nano technology and nanophotonics,devices are gradually evolving towards miniaturization,high response and low cost.Due to its ability to manipulate light at the nanoscale and independent of the material bandgap width,the hot electron photodetector based on surface plasmon has effectively solved the disadvantages of the traditional photoelectric converter,such as large volume and limited working band,and has played a very important role in the field of photoelectric conversion.At present,various hot electron photodetectors have been developed to work in optical communication windows and other wavebands,there are many two-dimensional materials and chips integrated photodetectors,which are widely used in biosensors,medical instruments,national defense,high-end manufacturing and other fields.In this dissertation,a series of work has been done on the photoelectric performance of two common structure types of the hot electron photodetector,and prepared one of them.The main research contents of this dissertation are as follows:(1)This dissertation comprehensively studies the photoelectric properties of metal-insulator-metal(MIM)structure hot electron photodetector through the finite element method,by optimizing the material and structure,the problem of the poor asymmetric absorption of the structure are solved and greatly improved the light trapping ability,effectively enhances the photoelectric performance of the device,the net absorption increased from 16% to 95% and the net responsivity increased from 1.85 n A/m W to 10.4n A/m W at the same resonance wavelength,achieved a narrowband response(FWHM=5.4nm).The influence of various structural parameters on the photoelectric characteristics of the device is studied,which provides guidance for optimizing the performance of the device.Finally,the photoelectric response insensitive to the polarization of incident light is realized by using the symmetry of the two-dimensional structure,and achieved perfect net absorption properties.(2)On the basis of previous studies,it aims to find a method for selective growth of thin films to solve the problem that the device obtained by the electron beam evaporation method does not match the model.First,the photoelectric performance simulation of the metal-semiconductor(MS)structure hot electron photodetector is studied.It was found that due to the relatively simple hot electron transfer mechanism of such structure and the thickness of metal film is small,the probability of hot electron being collected to form photocurrent is large,the photoelectric response was strong,the internal quantum efficiency is 2%,and the responsivity could reach 23.5m A /W at the resonance wavelength.Then,the device was prepared by electron beam evaporation and electrochemical method combined with electron beam lithography,the selective deposition of metal ions was observed by electrochemical method,which is not available by electron beam evaporation.The effect of film forming ability on the optical performance of the device was studied,and the principle was explained.