Modeling of Metal–Insulator–Semiconductor Dualband Si/SiO2 Multi-Quantum Well UV Detectors

Abstract

This article intends to propose a self-consistent theoretical model for Metal–Insulator–Semiconductor (MIS) dualband Si/SiO2 multi-quantum well (MQW) UV photodetector. Employing this model, general characteristics of MIS UV photodetectors such as dark and photocurrent density–voltage (J–V) curves are simulated. The results reveal that the proposed structure reduces dark current since first the resonant tunneling multi-barrier is designed such that the electron tunneling probability is unity at energies coincident with the peak detection wavelength, and secondly, tunneling significantly decreases at energies which are smaller than this optimum value and accordingly, transport of carriers contributing to the dark current, which have broad energy distribution at high temperatures, is inhibited. Moreover, the article demonstrates that the proposed structure can detect two individual x wavelengths in the UV range, simultaneously. The related absorption and responsivity curves are obtained and depicted. Defects in the SiO2 barriers are simulated indirectly by varying the electron effective tunneling mass in SiO2. Reductions in the SiO2 electron effective tunneling mass lead to an increase in dark current of the device.