Surface activation of Si-based Schottky diodes by bacterial biosynthesized AgInSe2 trimetallic alloy nanoparticles with evidenced negative capacitance and enhanced electro-dielectric performance

Semiconductor surface activation aims to modify the surface characteristics of a semiconductor material, such as its work function, surface energy, and chemical composition to improve its electrical properties and enable efficient charge transport across the device. Here, AgInSe2 complex trimetallic alloy was utilized as an interfacial layer in Si-based Schottky diodes and served as a semiconductor surface activator. The alloy nanoparticles were produced by green bacterial biosynthesis for the first time in the literature. XRD and micro-Raman manifested a nanostructured polycrystalline nature of the alloy with rhombohedral AgInSe2 and cubic Ag crystal phases. From the electrical measurements, the diode with AgInSe2 interfacial layer showed superior electrical and dielectric characteristics compared to the pure diode at room temperature. The introduction of interlayer resulted in a smaller ideality factor, larger barrier height, higher rectification ratio, lower leakage current, and better dielectric properties compared to the pure diode. The diode also recorded a negative permittivity, up to a certain frequency, that could enhance its performance when integrated into electronic circuits. The evidenced negative capacitance and its possible benefits in Schottky diodes are elaborated. The electro-dielectric enhancement was attributed to AgInSe2-induced semiconductor surface activation through the stimulation of the unpaired reactive silicon atoms at the semiconductor surface.