A Schottky device with structure (Ag/PVA-Ag-Coumarin/n-Si) has been fabricated for optical photodiode applications. It has been fabricated via a spin coating technique after preparing PVA-Ag nano-composite using the
in-situ technique and then adding Coumarin dye. The photodiode device has displayed good rectification
behavior proving the creation of Schottky junction. The high value of the junction parameters, e.g. series
resistance Rse = 15 kΩ, ideality factor n = 1.463, as well as height barrier ϕ = 0.779 eV are calculated from the
forward bias I–V characteristics at 50 mW/cm2 due to the interfaces between the fillers and PVA, creation of
barrier height at the interfaces between fillers and PVA, inhomogeneity of the barrier of an interfacial layer of
PVA, fabrication and surface processes. Interestingly, Ag/PVA-Ag-Coumarin/n-Si photodiode shows a rise time of
90.2 ms and fall time of 340.6 ms at 50 mW/cm2
. Also, C–V behavior suggested that the device significantly
relies on voltage and frequency. The significant increase in the capacitance in lower frequency and the existence
of a distinctive peak in the capacitance–frequency behavior refer to interface states. Thus, Ag/PVA-AgCoumarin/n-Si devices with their high light sensitivity, are brilliantly applicable in capacitance and/or photodiode sensors for many advantageous uses in modern optoelectronic and electronic industries. |
