Investigating charge transportation and photo-responsive outcome of a Schottky diode fabricated by 2-amino terephthalic acid directed supramolecular Mn(II)-metallogel

Abstract

This study investigates a supramolecular metallogel formed using an ultrasonication technique and employing manganese acetate tetrahydrate as a metal salt, 2-amino terephthalic acid (ATA) as an organic gelator, and N,N′-dimethyl formamide and dimethyl sulfoxide as mixed solvents. The mechanical toughness and viscoelastic parameters of the metallogel material were well demonstrated by rheology-based experimental values of storage and loss moduli with rotational frequency, shear strain, and shear stress of the Mn(II)-metallogel (Mn-ATA). The microstructural analysis along with chemical composition were shown using field emission scanning electron microscopy and energy dispersive X-ray analysis-based elemental research. Analysis of the infrared spectrum aided in determining how Mn-ATA was formed. Electrospray ionization mass investigation of Mn-ATA demonstrated the existence of several metallogel components and their engagement in producing the metallogel structure. Different diode parameters (i.e. photosensitivity, photoconductivity sensitivity, responsivity, specific detectivity, ideality factor, barrier height, and series resistance were measured, revealing the semiconducting property of the metallogel. The current–voltage characteristics of a Mn-ATA-based thin-film type metal–semiconductor junction device demonstrated non-linear rectifying behavior, indicating Schottky diode behavior with dominating electronic-charge transport features. The device displayed an improved rectifying property under illumination, which also implied higher conductivity. The device's measured conductivity in the low-voltage domain (equivalent to ohmic behavior) was 1.03 × 10−5 and 4.12 × 10−5 Sm−1 under darkness and illumination, respectively, implying photo-responsive behavior.