Suppressed Energy Transfer Loss of Dion–Jacobson Perovskite Enabled by DMSO Vapor Treatment for Efficient Sky-Blue Light-Emitting Diodes

Tuning the energy transfer in Ruddlesden–Popper perovskites phases through isopropylammonium addition – towards efficient blue emitters

“…But for blue-emitting PeLEDs, the progress in efficiency has been lagging behind, although many efforts have been dedicated to improving these devices. 12–25 Recently, a record EQE of 17.9% has been reported by ligand manipulation in on-substrate synthesis of quantum dots. 26…”

“…But for blue-emitting PeLEDs, the progress in efficiency has been lagging behind, although many efforts have been dedicated to improving these devices. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] Recently, a record EQE of 17.9% has been reported by ligand manipulation in on-substrate synthesis of quantum dots. 26 At least three major approaches have been used to fabricate efficient blue-emissive MHP layers with high values of photoluminescence quantum yields (PLQYs), which acts as a primary indicator for a promising emissive layers in emitting devices technology.…”

“…37 This relation between optical and structural-properties makes quasi-2D perovskites a promising candidate for light emission applications. Both Ruddlesden-Popper (RP) 17,21,29,30,38 as well as Dion-Jacobson (DJ) phases, 22,39,40 the two most common quasi-2D perovskites structures, already achieved remarkable performance in blue-emitting PeLEDs with record EQE above 15%. 21,22 RP phases are currently the most investigated, thanks to the more favourable formation energy of middle-n phases (such as n = 3) and the less efficient energy transfer from 2D to 3D phases, both key factors to obtain blue-emitting PeLEDs.…”

“…26 At least three major approaches have been used to fabricate efficient blue-emissive MHP layers with high values of photoluminescence quantum yields (PLQYs), which acts as a primary indicator for a promising emissive layers in emitting devices technology. 27 These three approaches rely on the use of active layers of very different nature, namely: (i) 3D MHPs, 15,25,28 (ii) quasi-2D perovskites, 17,21,22,29,30 and (iii) nanocrystals based on 3D MHPs. 16,23,31 The first approach has the advantage of the good charge transport properties of 3D perovskites, which contribute to improve the EQE.…”

Improving anion-exchange efficiency and spectrum stability of perovskite quantum dots via an Al3+ bonding-doping synergistic effect

“…9,10 Green and red perovskite QD light-emitting diodes (QLEDs) have shown external quantum efficiencies (EQEs) of over 20%, [11][12][13] and the EQE of blue perovskite QLEDs has reached 10%. [14][15][16] However, the development of deep-blue perovskite LEDs still lags significantly behind because of the difficulty of synthesizing high-quality deep-blue emission mixed-halide perovskite QDs, and the mismatched energy levels in the QLEDs.…”