3/10/09

Spectral responsivity of the quantum wire infrarednext term photodetectors

The main objective of this manuscript is to assign the optical response wavelength range that can be covered by this type of semiconductor-based photodetectors, quantum wire previous terminfrarednext term photodetectors (QRIPs). Also, the effect of quantum wire parameters (such as quantum wire density; lateral and transverse size), operating temperature, and applying bias voltage onto the behaviour of QRIPs are studied. From the obtained theoretical results, the maximum wavelength response is 40 μm at certain values of quantum wire density, lateral size and operating temperatures, 9.9×107 cm−2, aQR=15 nm, T=60 K, respectively. Another important observation is that the obtained calculated responsivity denotes the maximum value at an operating temperature of T=60 K, from a temperature range of 40–90 K, for the same QR parameter values. Meanwhile, in the case of lower values of the average quantum wire densities, the responsivity is normally decreased with increasing temperature. Moreover, increasing the applied voltage value will increase the number of mobile charges into the active region, which results in increasing each of the dark and photo currents. Hence, degradation into the spectral responsivity and detectivity will be noticed. For that, the applied biasing voltage should be around a moderate value, 0.5 V. Generally, the QRIPs can give multicolour response for (mid-, and far) (10 μm>λ>40 μm) the IR region depending on the selectable compound parameters of QRIPs.