基於掌性鈣鈦礦的發光二極體

Abstract

本篇研究旨在引入具有對映異構物特性之「掌性」有機長鏈分子R/S-MBA，在這個基礎之下合成準二維掌性鈣鈦礦R/S-(MBA)2(MA0.2Cs0.8)Pb2Br7作為主要研究目標，最後製成發光二極體後並探討其旋光特性。第一部份研究使用準二維掌性鈣鈦礦R/S-(MBA)2(MA0.2Cs0.8)Pb2Br7作為「發光層」或「掌性選擇層（有機螢光材料Superyellow（Super yellow light-emitting PPV copolymer）作為發光層）」，透過比較其左掌性或右掌性的旋光特性進行各項量測並探討其光電特性。在這項實驗中，我們發現掌性鈣鈦礦在做為發光層時電致發光無法表現出明確的旋光特性；但在做為掌性選擇層時能夠發揮良好的左旋或右旋之選擇性，使得電致發光能明確分辨出左旋光或右旋光。第二部份研究中，本文使用R-(MBA)2(MA0.2Cs0.8)Pb2Br7作為發光層並透過添加不同比例之3-(Decyldimethylammonio)­propane­sulfonate inner salt（Caprylyl sulfobetaine，SB3-10），成功地將元件之效率由0.767%提升至2.304%。其關鍵在於引入此穩定劑能夠與鈣鈦礦晶粒邊界上的陰、陽離子作用進而鈍化鈣鈦礦薄膜中晶粒的表面缺陷，達到改質的效果。This research aims to introduce the chiral organic long-chain molecule R/S-MBA with enantiomeric properties in order to synthesize the Quasi-2D chiral perovskite R/S-(MBA)2(MA0.2Cs0.8)Pb2Br7 as the main research target. We will then fabricate it into a light-emitting diode and explore its photoelectric properties.The first part of the research mainly focuses on using the Quasi-2D chiral perovskite R/S-(MBA)2(MA0.2Cs0.8)Pb2Br7 as the emission layer or as the chiral selective layer (with the organic fluorescent material Superyellow, a Super yellow light-emitting PPV copolymer, as the emission layer). By comparing the optical rotation characteristics, various measurements were made, and its photoelectric properties were discussed. In this experiment, we found that the electroluminescence of the chiral perovskite does not show clear optical rotation characteristics when used as the emission layer. However, it can exhibit good left-handed or right-handed selectivity when used as a chiral selective layer, thereby allowing electroluminescence to clearly distinguish between left circularly polarized light and right circularly polarized light.In the second part of the study, we used R-(MBA)2(MA0.2Cs0.8)Pb2Br7 as the emission layer and added different proportions of 3-(Decyldimethylammonio) propanesulfonate inner salt (SB3-10), successfully increasing the external quantum efficiency (EQE) from 0.767% to 2.304%. The key is that the introduction of this stabilizer can interact with anions and cations on the boundaries of perovskite grains to passivate the defects on the grain surface in the perovskite film, achieving surface modification.