طراحی آشکارساز مادون قرمز- میانی چاه کوانتومی دو طول موجه مبتنی بر ساختار آبشاری

In this paper, a quantum well infrared photodetector based on cascade structure is proposed which is capable of simultaneous detection of two different wavelengths in mid-infrared region. The active region of this photodetector is monolithically sensitive to both wavelengths and the electron transport system is designed to transport electrons excited by two different wavelengths. By attaching a capturing well to the active region a common transportation path for electron excited by two different wavelengths is realized. Calculated values for responsivity and detectivity in this structure are: R ( 6.85 m) 67.5mA W 1 l = m = , R ( 12.35 m) 118.5mAW 2 l = m = , * ( ) 7 1 D l = 6.85 = 6.89´10 J , * ( ) 8 2 D l =12.35 =1.2´10 J at 120K temperature, respectively.