FABRICATION AND INVESTIGATION CHARACTERISTICS OF SILVER/ NANO CRYSTAL POROUS SILICON/N-TYPE CRYSTAL SILICON HETERO JUNCTION UV-VISIBLE PHOTO DETECTOR
HASAN A. HADI *
Department of Physics, College of Education, Al-Mustanseriyah University, Iraq
*Author to whom correspondence should be addressed.
Abstract
In this paper, mono crystalline n-type wafer silicon was used to form Ag/PS/n-Si heterojunction photo-detector PD on porous silicon layer by using a photo electrochemical etching (PECE) technique. The surface profiles were analyzed by atomic force microscopy and optical microscopy and the porosity of the silicon layer was 79%. A comprehensive study of the Ag/PS/n-Si photo detector in terms of the properties of synthetic porous silicon, as well as electrical characteristics showed that the values of ideality factor, shunt and series resistance, and Schottky barrier height were Convergent with each other which when measured by current-volt (I-V) or capacitance-volt (C-V). The Ag/PS/n-Si device in this work shows a high sensitivity in near UV and visible regions. The values of responsivity and Quantum efficiency were 0.38A/W and 108% for near to visible region, while near to the UV region were 0.33A/W and 118% respectively.
Keywords: Porous silicon, photo-electrochemical etching, heterojunction, photo-detector;, responsivity; quantum efficiency