Lead Halide Perovskite Nanocrystals: Room Temperature Syntheses toward Commercial Viability

Abstract

In this progress report, recent improvements to the room temperaturesyntheses of lead halide perovskite nanocrystals (APbX3, X = Cl, Br, I) are assessed, focusing on various aspects which influence the commercial viability of the technology. Perovskite nanocrystals can be prepared easily from low‐cost precursors under ambient conditions, yet they have displayed near‐unity photoluminescence quantum yield with narrow, highly tunable emission peaks. In addition to their impressive ambipolar charge carrier mobilities, these properties make lead halide perovskite nanocrystals very attractive for light‐emitting diode (LED) applications. However, there are still many practical hurdles preventing commercialization. Recent developments in room temperature synthesis and purification protocols are reviewed, closely evaluating the suitability of particular techniques for industry. This is followed by an assessment of the wide range of ligands deployed on perovskite nanocrystal surfaces, analyzing their impact on colloidal stability, as well as LED efficiency. Based on these observations, a perspective on important future research directions that can expedite the industrial adoption of perovskite nanocrystals is provided.

Progress in halide-perovskite nanocrystals with near-unity photoluminescence quantum yield

“…One encouraging approach to prepare high-quality PNCs is through the ligand-assisted reprecipitation technique (LARP). This protocol is simpler, lower cost, faster, and requires milder conditions, being suitable for organic nanomaterials [88,89]. Pérez-Prieto and coworkers [90] have synthesized MAPbBr 3 nanoplatelets with unity PLQY by preparing solutions containing certain amounts of MABr, PbBr 2 , and 2-adamantylammonium bromide (ADBr) in DMF.…”

“…(B) Evolution of the PLQYs of washed PNCs according to the different methodologies. See[5,25,52,53,55,58,64,[66][67][68]72,74,82,86,88,97].…”

Recent Advances in Blue Perovskite Quantum Dots for Light‐Emitting Diodes

“…The valence band is determined by the np orbitals of the halogen and the 6s orbitals of Pb 2+ , while the conductive band is hybridized by the 6p orbitals of Pb 2+ and np orbitals of halogen [56,60] (Figure 3a). When the halogen changes from Cl (3p 6 ) to I (5p 6 ), the energies of the np 6 orbitals increase, shifting the valence-band maximum (VBM) toward more negative potential. [2,61] Therefore, varying the halogen from Cl to Br can decrease the bandgap and tune the emission from blue-violet to sky-blue.…”

“…In addition, their cost-effective solution synthesis process facilitates the massive fabrication for prospective commercial applications. [5,6] These superior properties make them widely applied for diverse optoelectronic applications, [7][8][9][10][11][12] including solar cells, lasers, photodetectors, and light-emitting diodes (LEDs). Specifically, owing to the compelling emission features, they are deemed as ideal next-generation fluorescent materials for high-quality full-color display and lighting.…”

Room‐Temperature Direct Synthesis of Tetragonal β‐CsPbI3 Nanocrystals

“…[13][14][15][16][17][18][19][20][21] Typically, they can be synthesized through the hot-injection method under inert gas protection, which usually produce NCs with good crystal quality but low synthetic yield, thus is not applicable for low cost massive production. [22] In contrast, the solvent induced reprecipitation at room-temperature (RT) has been demonstrated as a convenient and low-cost route to fabricate CsPbX 3 (X = Cl and/or Br) NCs. [22][23][24][25][26] However, this method still failed to synthesize CsPbI 3 NCs since strong polar solvent, i.e., dimethylformamide (DMF), were used during reaction, which will induce phase transition or decomposition.…”