2 Dimensional Layered Structures ofBismuth Oxyiodide andTriiodide Based Photoactive Perovskite Materials

Abstract

The main objective of this thesis is to develop and encompasses work on three newlinedifferent crystalline materials of the two-dimensional (2D) layer semiconductors community (BiOX, BiX3, and ABX3). Chapter-I - A brief introduction about two-dimensional (2D) layer structures developed in a new strategy and novel fabrication methods of layer structures, as well as the exploration of their unique characteristics and application in core issues. newlineChapter-II- A simple solution-based synthesis of bismuth oxyiodide (BiOI) using different concentration of HNO3. Tuning the morphologies from a bowl, square sheets to star shapes were controlled by varying the concentrations of precursors (Bi:I) contains HNO3. The time-dependent growth of high dense bowls, square sheets and star-shaped morphologies was identified at room temperature condition, respectively. We have developed a general approach to fabricate BiOI/Polymer nanocomposite thin films and demonstrated by employing them in PVA(polyvinyl alcohol) matrix to form BiOI-PVA composite material used as a dip catalyst for photo-degradation of a dye respectively. Chapter-III -The work presented in this thesis demonstrates the simple protocol that synthesis the 2D LBL structures of BiOI at intermediated supersaturation conditions. Anisotropic crystal growth of BiOI layer-by-layer (LBL) structures are identified by using powerful microscope techniques like TEM, FESEM, and AFM studies. The vertically aligned Au nanoparticles on the surface of BiOI effectively prevent aggregation and long-term stability to form hybrid Au-BiOI. The detection of dye molecules (R6G) using BiOI and Au-BiOI substrates shows enhancement of surface-enhanced Raman scattering (SERS) studies was also demonstrated. The visible light photodetectors performance using BiOI and Au-BiOI shows a good reproducibility with maximum responsivity. Chapter-IV-We study the piezotronic behavior of BiI3 single and twin plates morphologies using a two-terminal electrode system. Set of experiments using high nitric acid..