Abstract
Metal halide perovskites have received much attention for their application in light-emitting diodes (LEDs) and solar cells in the past several years. Among them, 2D and quasi-2D perovskite with organic long-chain cations introduced have drawn significant attention. However, while improving wet and thermal stability, as the grain size becomes smaller, more defects introduced at the grain boundary and surface, resulting in the increase of non-radiative recombination is becoming the main problem which should be faced by 2D/quasi-2D perovskite materials. Here, we report a new strategy employing ionic liquid named 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(EMB).By adding a small amount of ionic liquid to the precursor, the defect was effectively passivated and the photoluminescence intensity was increased by 11 times and the fluorescent lifetime was increased by about 1.5 times. The flatness of the prepared perovskite thin films has also been effectively improved.
Highlights
Due to the advantages of high luminous efficiency, high quantum yield, pure color and adjustable band gap, metal halide perovskites has attracted great attention of researchers recently[1-9]
Compared with the film without Ethyl-3methylimidazolium bis(trifluoromethylsulfonyl) imide (EMB) added, the PL intensity was significantly increased by about 911 times when ionic liquids was introduced in different ratio.Among them, 5 wt% EMB added has a maximum PL intensity, approximately 11 times than the initial
The emission peak of the pristine perovskite film was located at around 520 nm. while the PL peak of the perovskite films with ionic liquids-treated located at about 514 nm was slightly blue-shifted
Summary
Due to the advantages of high luminous efficiency, high quantum yield, pure color and adjustable band gap, metal halide perovskites has attracted great attention of researchers recently[1-9]. The two/quasi-two-dimensional perovskite structures formed by introducing organic long-chain cations to cut threedimensional bulk phase are attracting more and more attention.The chemical formula of quasi-2D perovskite is demonstrated as L2An-1BnX3n+1, where L represents large-size organic spacer cations , such as phenylethylamine (PEA) and butylamine (BA) , A represents monovalent cation(Cs+、MA(CH3NH3+)、 FA(HC(NH2)2+ etc.). The X represents halogen anions(I−, Br−, Cl− etc.). The introduction of organic long-chain cations improves the hygrothermal stability of quasi-two-dimensional perovskite. Morever,organic long-chain cations is possible to confine the structural freedom, stabilize the oriented structure, and favor to form 2D perovskite film with better crystallinity and orientation[10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
