Abstract
The design and characterization of indigo dye (C.I. Vat Blue I) have analyzed by several techniques such as XRD, FTIR; optically diffused reflectance based on the Kubelka-Munk model and electrical conductivity/dielectric 'properties that can use as natural organic semiconductor dyes. The XRD measurements revealed that the indigo dye has crystallized for the first time by using Crysfire and Check-cell assignment software in orthorhorribic structure with a space group (P-222) and both the optimized lattice and refinement cell parameters have calculated before and after refinement. FTIR supports the fingerprint groups of indigo dye. Based on the Kubelka-Munk model, it has noted that there are two optical transition bands equal to 1.847 eV and 1.721 eV related to the multi-graded band gap of the indigo dye that enhanced the light absorption and can make the indigo material to be used in solar cell and optoelectronic applications. The AC/DC electrical conductivities as function frequency/temperatures, respectively, parallel/series dielectric properties (real/imaginary parts) have investigated and interpreted by using the two-probe electrical conductivity measurement. The AC conductivity and dielectric properties can support the charge-hopping carriers of barriers of various heights. Indigo dye is a highly stable organic dye for new organic devices and technologies. (C) 2017 Elsevier Ltd. All rights reserved.