新型复合盖层延伸波长InGaAs红外探测器结构优化设计

Abstract

The near-infrared detector of In0. 82Ga0. 18 As with PIN structure was designed and simulated by APSYS. The long-wave cutoff wavelength was extended to 2. 6 μm. Three doped layers were deposited on the absorption layer,which contained P type N type,N type and by growth order. The thickness and concentration of each doped layer in cap layer were analyzed. The results show that In0. 82Ga0. 18 As,In As0. 6P0. 4and In0. 82Al0. 18 As layers by growth order are determined to obtain the excellent performance. The relative spectral responsivity of the detector keeps almost the same,and dark current decreases by one magnitude compared with the PIN structure. The defect tunneling current predominates when the detector works at 120- 250 K,the inter-band tunneling current dominates the dark current when the detector works at 250- 300 K,and the G-R current and diffusion current dominates the dark current when the detector works above 300 K.