Research On The Optoelectronic Characteristic Of Tamm Plasmon Enhanced Hot Electron Photodetectors

In the research of conventional optoelectronic devices,we often takes the light absorption of metal materials as the loss part of the total incident solar energy and want to prevent this absorption.But we can also take use of this part of absorption in a kind of devices called plasmon-enhanced hot electrons devices.It is usually nano-structured because the excitation of Surface Plasmons(SPs)near the interface between metal nano-structure and air can largely improve absorption in the materials.And beside conventional SPs mechanism,researchers found a new type of surface resonate state called Tamm Plasmons(TPs)which can be excited by a kind of simple multi-layers plain structure.There are amount of applications of these plasmon-enhanced hot electrons devices,and hot electron photodetectors(HEPDs)is one of them.We can engineering the structure of HEPDs to achieve high tunability,high sensitivity and narrowband absorption in special frequency band,so it has been widely researched in recent years.We analyse a kind of HEPDs based on the excitation of TPs and a kind of HEPDs based on the structure of nano-grating,and engineer the structure parameters of them to improve optical and electrical response performance of HEPDs.And we propose a new structure which combine multi-layers plain structure and metal nano-grating structure.By optical and electrical simulations,we archive much higher electrical response performance than former HEPDs.The main works in this thesis are listed as follows:(1)We calculate the absorption spectrum of DBR multi-layers structure HEPDs and metal nano-grating structure HEPDs.We discuss the target resonant wavelength,magnitude of the absorption peak and full width half maximum(FWHM)of the device under different structure parameters including number of DBR layers,Bragg wavelength,the grating period,the width and height of the grating,etc.And we find that a group of parameters can achieve very high absorptance near 820 nm.(2)We design the new structure which combine multi-layers plain structure and metal nano-grating structure,achieving coupling of TPs and SPs and geting new resonant modes.Through simulations,we find that we can get highly efficient coupling mode in the wavelength near 820 nm.(3)We use formulas in Drude models and the EDJDOS method of hot electrons distribution to calculate responsibility and optoelectronic conversion efficiency of the devices.In our structures,responsibility can be 0.4m A/W which is 4 times higher than conventional devices.