Visible-Blind UV/IR Photodetectors Integrated on Si Substrates

Abstract

ABSTRACTA concept based on structures fabricated using stacked semiconducting layers to obtain a multi spectral photoresponse is investigated. Issues related to III nitride layer growth on thin Si wafers, such as substrate temperature recalibration and mechanical stress due to the lattice mismatch, have been studied. The grown on Si substrate III nitride layers were characterized by using spectroscopic ellipsometry and capacitance measurements. 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.