Investigation On Si-based Terahertz And Infrared Detectors

The research of detectors is an important and basic content in the field of infrared?IR?and terahertz?THz?.The rapid development of IR and THz detection technology to meet the requirements in the area of imaging,atmospheric remote sensing,biomedicine imaging put forward to higher requirements of the performance on detectors.It is urgent need to achieve IR and THz detection with the directions of room temperature,fast response,high sensitivity and easy to array integration.Based on the novel THz detection mechanism proposed by the research group,a Si-based THz photoelectric detector with metal-semiconductor-metal?MSM?structure was successfully fabricated and showed broadband and fast response from the microwave to the THz radiation at room temperature.In addition,Room temperature,broadband IR thermal detection was investigated for the first time by using Mn_1.56Co_0.96Ni_0.48O₄?MCNO?thin film with dielectric-metal-dielectric absorptive layers,which was constructed to improve the light absorption.The main content and innovations are as follows:?1?To further demonstrate its generality of our proposed electromagnetic induced wells?EIW?mechanism and achieve the optoelectronic integration of terahertz detectors,silicon-based materials are applied to the EIW mechanism for the first time in this paper.The simple structure and easy integration of the Si-based detector,which provides an avenue to the optoelectronic integration of sensitive room-temperature terahertz focal-plane arrays.?2?A small-sized Si-based detector with the MSM structure was fabricated by semiconductor technology based on the P-type silicon material with SOI structure,and the performance parameters such as responsivity,equivalent noise power time constants were characterized by a microwave and THz measure system.The Si-based detector achieved broadband detection and showed excellent performance.It achieved a maximal responsivity of 49.3 kV/W and noise-equivalent power?NEP?of 0.38pW/?Hz at 20-40 GHz,and achieved a responsivity of 3.3 kV/W and NEP of 5.7pW/?Hz at 0.165-0.173 THz;Moreover,a short response time?810 ns was realized for the detector.?3?The MCNO material has a low absorption for incident light and is selective over a broadband range.Therefore,we designed and fabricated a dielectric-metal-dielectric?Si₃N₄/NiCr/SiO₂?structured absorptive layer for MCNO film detector for the first time,which enhanced the absorption in the 3-14?m IR transparent range of MCNO film.?4?The MCNO films with good performance were prepared by magnetron sputtering deposition and chemical solution deposition method.Firstly,the film crystallinity and morphological properties were measured by XRD and SEM,MCNO film has good crystallinity and negative temperature coefficient;Then it was prepared to have absorption structure and no absorption structure.The detectors with absorptive layers and no-absorption layers were prepared for contrast experiments.Through the measure of the responsivity,noise,time constant and detectivity of the MCNO thin film devices,it was found that responsivity and detectivity of the detectors with the absorptive layers for the blackbody radiation improved significantly compared with the detector without the absorptive layers.