Metal Halide Perovskite Quantum Dots for Thin-Film Transistors

• Autor(a) principal: Ferreira, Rodrigo Lourenço do Espírito Santo Rosa
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/141862
• topic: Quantum Dots; Metal Halide Perovskite; TFT; State-Resolved; High Photoluminescence; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

The re-emergence of metal halide perovskites has been revolutionizing the optoelectronic field, particularly photovoltaics, where within just a few years, remarkable power conversion efficiencies over 28% have been achieved. However, we turn our attention to exploiting perovskites for the production of thin-film transistors (TFTs), owing to their high solution processability and excellent transport characteristics, whilst aiming to overcome their shortcomings, deeply interconnected to their poor stability. In this work, two different organic lead halide perovskite quantum dot (QD) compounds were synthesized, FAPbBr3 and FAPbI3, yielding exceptional photo-physical properties with green and near-infrared (NIR) emission, respectively. A novel synthesis method for the FAPbI3 QDs was carried out, which revealed extremely stable nanocrystals (NCs) with very bright photoluminescence. For FAPbBr3, two different synthesis methods established in the literature were undertaken and compared, resulting in devices exhibiting photogating characteristics, with ILight /IDark ratios over 103, and field effect mobilities of 1.63×10−3 and 2.06 cm2 V−1 s−1, in dark and light environments, respectively. Additionally, novel state-resolved behaviour was observed, indicating band-like charge transport through the discrete QD states, accredited to smaller particles, implying high-quality, monodisperse QDs, which can provide critical insight on the nature of these materials.