Synthesis of Cs/Methylammonium/Formamidinium PbBr₃ Perovskite Nanocrystals with Green Emissions: Implications for Display Applications

Abstract

A facile synthesis of green-emitting all-inorganic (CsPbBr 3 ) and organometallic [methylammonium (MA)PbBr 3 and formamidinium (FA)PbBr 3 ] perovskite nanocrystals (NCs) with near-unity photoluminescence quantum yields, narrow emission bandwidths (fwhm < 22 nm), and much improved colloidal stability has been reported here. A low-cost and highly reactive bromide precursor 1,3-dibromo-5,5-dimethylhydantoin was employed in our synthesis that not only rendered excellent stability to all three NCs (Cs/MA/FAPbBr 3 ) but also eased the synthesis of high-quality MAPbBr 3 NCs even at moderate temperatures. At high temperatures, MAPbBr 3 NCs decompose by releasing gaseous methylamine, making their synthesis a difficult task in conventional high-temperature hot injection method. Our synthesized NCs are coveted materials exemplified by their narrow particle size distributions, excellent colloidal stability in ambient conditions, and high tolerance toward UV light and polar solvents. All these astonishing properties signify their better suitability in real applications like displays, low-threshold lasers, and light-emitting diodes.

CsPbBr3 in the Activation of the C–Br Bond of CBrX3 (X = Cl, Br) under Sunlight

“…The CsPbBr 3 perovskite NCs were synthesized by the hot-injection method by following a reported procedure. − However, we used dibromoisocyanuric acid for the first time as a Br precursor. A powder X-ray diffraction (PXRD) analysis confirmed the orthorhombic structure as the unique diffraction peak obtained at ∼13° corresponds to the (101) crystal plane along with other characteristic peaks (Figure a). , Surprisingly, this pattern is different from those of other reported CsPbBr 3 perovskites, which showed cubic structures where NBS and DBHT are used as bromide precursors (Table ). The uniform morphology with a narrow size distribution (an average edge length of 8.3 nm) of CsPbBr 3 NCs was confirmed by transmission electron microscopy (TEM) (Figure b).…”

On direct synthesis of high quality APbX3 (A = Cs+, MA+ and FA+; X = Cl−, Br− and I−) nanocrystals following a generic approach

“…[9][10][11][12][13][14] Increasing demand for various lighting and display technologies has generated huge interest in developing methodologies for the preparation of high quality perovskite NCs. 8,12,15,16 While these studies helped targeted synthesis of violet, green or redemitting all-inorganic and/or hybrid NCs, 6,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] no generic method of obtaining all these systems with good optical properties and stability is reported to date despite intense efforts. For example, Pradhan and co-workers obtained CsPbX 3 (X = Cl, Br and I) NCs with near-unity PLQY, but not the hybrid systems.…”

Recent progress of single-halide perovskite nanocrystals for advanced displays

“…Methods to increase the intrinsic stability include A-site and B-site cation engineering to increase the structural stability of perovskites. 134,135 Smaller B-site doping was used to obtain highly efficient and structural stability by inducing lattice contraction. 31,73 Moreover, the epitaxial incorporation of NCs within a semiconducting shell seems to be an efficient strategy (Fig.…”