Executive Summary : | The lead halide perovskites (HPs) demonstrated remarkable potential in photovoltaics, despite attaining remarkable performance with lead-based HP optoelectronic devices, environmental stability, Pb toxicity, and perovskite degradation hinder the practical utilization. Recently, the halide double perovskites (HDPs) are emerged as an alternative HP with high carrier mobility and long carrier diffusion lengths, facilitating environmentally benign, and low-temperature solution processibility motivated the research in HDP-based FETs. The development of HDP FETs is in the preliminary stage and needs more understanding of the key properties such as ion migration, the interfacial trap states, and interstitial vacancies. Here, PI propose the synthesis of HDP MCs using a simple and scalable hot spin-casting method, which enables the control over the shape, size, and facet orientation of HDP MCs. The HDP MCs provide direct access to the intrinsic properties of materials devoid of defects and grain boundaries to deliver intrinsic charge carrier mobilities and enhanced carrier diffusion lengths, compared to nano or polycrystalline structures. The facet orientation of MCs parallel to the substrate drastically improves the charge transport properties and exhibits high resilience to interstitial and vacancy defects. The capping agent and ligand-free synthesis of HDP MCs facilitate barrier-free charge transport at the metal/HDP interface for the fabrication of HDP MC-based FETs. More importantly, the proposed cation/anion engineering in facet-oriented HDP MCs restrains space charge confinement at the dielectric semiconductor/HDP interface to eradicate hysteresis in HDP FETs. The project is also focused on understanding the contact resistance, parasitic effects, and charge transport behavior of HDP MCs in FET architecture, which will pave a path for translating the devices into a tangible technology. |