ABSTRACT
Employment of layered structures made of semiconductor materials with different optical absorption bands, is a new way of realizing either a broad spectrum photodetector or selective multiple band photodetectors. Such a concept based on structures fabricated using stacked semiconducting layers to obtain a multi spectral photoresponse is investigated in this paper. Based on the selected approach, fabrication of a dual-band UV/IR photodetector with a reasonable responsivity at room temperature has been demonstrated. The integrated device is capable of detecting optical emissions separately in the UV and IR parts of the spectrum. The responsivities of this device are ~0.01 A/W, at a peak wavelength of 300 nm and ~0.08 A/W, at a peak wavelength of 1000 nm, respectively. The described dual-band photodetectors can be employed for false alarm-free fire/flame detection and advanced hazardous object or target detection and recognition in several industrial, military, and space applications.
