In Situ Fabrication of Highly Luminescent Bifunctional Amino Acid Crosslinked 2D/3D NH 3 C 4 H 9 COO(CH 3 NH 3 PbBr 3 ) n Perovskite Films

The perovskite quantum dots are usually synthesized by solution chemistry and then fabricated into film for device application with some extra process. Here it is reported for the first time to in situ formation of a crosslinked 2D/3D NH 3 C 4 H 9 COO(CH 3 NH 3 ) n Pb n Br 3 n perovskite planar films with controllable quantum confine via bifunctional amino acid crosslinkage, which is comparable to the solution chemistry synthesized CH 3 NH 3 PbBr 3 quantum dots. These atomic layer controllable perovskite films are facilely fabricated and tuned by addition of bi‐functional 5‐aminovaleric acid (Ava) of NH 2 C 4 H 9 COOH into regular (CH 3 NH 3 )PbBr 3 (MAPbBr 3 ) perovskite precursor solutions. Both the NH 3 + and the COO − groups of the zwitterionic amino acid are proposed to crosslink the atomic layer MAPbBr 3 units via PbCOO bond and ion bond between NH 3 + and [PbX 6 ] unit. The characterizations by atomic force microscopy, scanning electron microscopy, Raman, and photoluminescence spectroscopy confirm a successful fabrication of ultrasmooth and stable film with tunable optical properties. The bifunctional crosslinked 2D/3D Ava(MAPbBr 3 ) n perovskite films with controllable quantum confine would serve as distinct and promising materials for optical and optoelectronic applications.