Influence of the mixed cation in lead iodide based perovskite on the performance of resistive random access memory

Abstract

This research involves two parts The first part discusses the effects of doping different concentrations of formamidinium iodide (FAI) into MAPbI3 perovskite on the properties of perovskite based films and photovoltaic devices Since the ionic radius of formamidinium (FA+) is larger than that of methylammonium (MA+) the FA doping increases the tolerance factor and forms a stable cubic perovskite phase enhancing the grain size of the film and reducing the marginal effect of the grain boundary that improves the light absorption of the perovskite layer In the case of resistive random access memory (RRAM) device the addition of FAI stabilizes the crystal structure of the perovskite improving the stability of device that results in a significant increase in the number of memory cycles When 75% FAI was doped in perovskite the RRAM device performs about 100 memory cycles The second part of this thesis discusses the optimization of the parament characteristics of FAxMA1-xPbI3 perovskite that was doped with Cesium iodide (CsI) The crystallinity was improved by the CsI doping and a high-quality and highly covered perovskite film with reduced defects In the case of RRAM device the on/off ratio can be stabilized When 5% CsI is doped the RRAM device has about 120 memory cycles and on/off ratio reaches 10000

Date of Award	2019
Original language	English
Supervisor	Chuan-Feng Shih (Supervisor)