Methylammonium Lead Iodide thin films grown by Pulsed Laser Deposition for Photodetector Applications

Abstract

This thesis studies the fabrication and characterization of Methylammonium Lead Iodide perovskite thin films for photodetector applications. Unlike, any other perovskite halide material, Methylammonium Lead Iodide perovskite has long range balanced electron and hole transportation lengths. A major challenge is to use such materials to grow fine quality thin films. We tried to grow these perovskite thin films by the Pulsed laser deposition (PLD) technique, which is well known and successful in areas such as metal oxide-based complex perovskite systems. The unique ability to transfer from the bulk to a film with original Stoichiometry is the main strength of this technique. The first chapter provides a brief overview of the halide Perovskites and their properties such as optoelectronic properties, Ferroelectric property and thermal conductivity. In the second chapter, we describe the Pulsed laser deposition (PLD) technique used for the synthesis of the thin films. The invention of PLD technique has helped the fabrication of high-quality uniform thin films over a large area on the substrate. Understanding the pros/cons of PLD technique helps us in identifying the novelty of the thesis work. The second chapter also describes material growth techniques and all the characterization techniques that provide foundation for the entire thesis. In the third chapter, we describe the application of the CH3NH3PbI3 thin films grown by pulsed laser deposition for photodetection applications. With this method, we obtained good perovskite films coverage on fluorine-doped tin oxide coated substrates and observed well developed grains. The films showed no sign of degradation over several months of testing. We investigated the surface morphology and surface roughness of the films. We carried out a study on the solar and infrared photodetection of CH3NH3PbI3 thin films. In the fourth chapter, we describe the effect of change in annealing temperature and annealing time by keeping the thin film fabrication parameters constant...