Abstract
The use of the optical matrix method for computing the energy states and transmission probability in the bound-to-miniband (BTM) and step-bound-to-miniband (SBTM) transition III-V quantum well infrared photodetectors (QWIPs) is described. The effect of exchange energy due to electron-electron interaction was taken into account in the calculation of the Fermi level in the quantum well. Numerical simulations of the dark current as a function of temperature and bias voltage have been performed for both BTM and SBTM QWIPs. It is shown that dark current in these miniband transport QWIPs is dominated by the thermionic-assisted tunnelling conduction via the miniband for T>or=60 K, whereas resonant tunnelling conduction prevails for T<or=40 K. The results show that a significant reduction in dark current can be achieved for the BTM QWIP as compared with that of a conventional GaAs QWIP.