Research On Multi-quantum Well Infrared Detector With 2D Grating Structure

In recent years,the third-generation infrared detector has been extensively studied,characterized by high detection rate,low cost,large area array,and multi-spectral,the most representative ones are Hg Cd Te detectors,quantum well detectors and antimonide type-II superlattice detector.Among them,quantum well infrared detectors have made great progress in research so far.For Ga As / Al Ga As quantum well infrared detectors,due to the mature material preparation technology and perfect device manufacturing process,it has great application potential in the manufacture of two-color or multi-color infrared focal plane array devices.At the same time,the detector belongs to an extrinsic photo-conductivity mechanism,which relies on the optical transition of electrons(holes)between different subbands of the same conduction band(valence band).so it cannot directly absorb infrared rays incident perpendicular to the growth surface of the multiple quantum well Light is generally absorbed through light coupling.The traditional optical coupling is achieved by grinding the foot 45 degrees on the side or preparing a one-dimensional or two-dimensional coupling grating on the surface.This article introduces a new technology for preparing two-dimensional surface gratings on quantum well infrared detectors using microsphere etching technology.Compared with other methods,the preparation cost and technical difficulty are effectively reduced.In this paper,a multi-quantum well infrared detector with a two-dimensional grating structure on the surface was prepared using microsphere etching technology.And made a detailed experimental study on the coupling performance of the grating and the photoelectric performance of the detector.The research content mainly includes the following aspects:(1)Introduce the background of this article,reported the current development history of infrared detectors,briefly introduced the types and working principles of current infrared detection types;Introduced the research status and research of multi-quantum well infrared detector and multi-quantum well infrared detector optical coupling solution,and analyzed their advantages and disadvantages.(2)The basic principle of the multi-quantum well infrared detector is introduced,focused on the energy band structure design of the detector and several important parameters characterizing performance;The optical principle of the surface.(3)two-dimensional grating is studied,and the technological process of preparing the surface two-dimensional grating by the microsphere etching technologyis explored.A complete set of methods can be summarized to prepare the two-dimensional grating for the detector surface with different detection wavelengths.(4)Two-dimensional grating structure with coupling wavelength of 6 ? 9um was prepared by using micro-ball etching technology,and the influence of different process conditions on coupling effect was explored.A multi-quantum well infrared detector with a two-dimensional grating on the surface and a traditional multi-quantum well infrared detector with a 45-degree edge coupling were prepared,and the photoelectric performance of the two was tested,and the reasons for the difference in the photoelectric performance of the two were analyzed.