Recently, perovskite quantum dots (QDs) have attracted intensive interest due to their outstanding optical properties, but their extremely poor chemical stability hinders the development of the high-performance perovskite QD-based light-emitting diodes (PeLEDs). In this study, chemically stable SiO2-coated core–shell perovskite QDs are prepared to fabricate all-solution-processed PeLEDs. When the SiO2 shell thickness increases, the chemical stability of perovskite QDs is dramatically improved, while the charge injection efficiency is significantly decreased, which becomes the biggest obstacle for PeLED applications. Thus, controlling the SiO2 thickness is essential to obtain core–shell perovskite QDs optimal for PeLEDs in an aspect of chemical and optoelectrical properties. The 3-aminopropyl-triethoxysilane (APTES)/oleylamine (OAm) volume ratio is found to be a critical factor for obtaining an ultrathin SiO2 shell. Optimization of the APTES/OAm ratio affords A-site-doped CsPbBr3 QDs with an ultrathin SiO2 shell (A-CsPbBr3@SiO2 QDs) that exhibit longer radiative lifetimes and smaller shallow trap fraction than those without A-site doping, resulting in a higher photoluminescence quantum yield. A-CsPbBr3@SiO2 QDs also demonstrate long-term superior chemical stability in polar solvents without loss of optical properties due to passivation by the SiO2 shell and less defects via A-site doping. Consequently, all-solution-processed PeLED is successfully fabricated under ambient conditions, facilitating perovskite QD utilization in low-cost, large-area, flexible next-generation displays.

Molecular ordering of organic semiconductors comprising a newly designed A(D–A′–D)2 system was achieved through hydrogen bonding after removal of tert-butyloxycarbonyl substituents.

Perovskite quantum dots (QDs) have been extensively studied as emissive materials for next-generation optoelectronics due to their outstanding optical properties; however, their structural instabilities, specifically those of red perovskite QDs,...

(E)-6,60 -Dibromo-1,1-bis(2-octyldodecyl)-(3,3 0 -biindolinylid-ene)-2,2 0 -dione and/or 2,5-bis(2-octyldodecyl)-3,6-di(5-bromothien-2-yl)pyrrolo [3,4-c]pyrrole-1,4-(2H,5H)-dione and their tBoc-counterparts were propagated with 2,5-bis(tributylstannyl)thiophene in a molar ratio of 0.8 : 0.2 : 1.0 to release P(ODIDT-BID), P(ODIDT$BDPP), P(ODDPPT$BID) and P(ODDPPT$BDPP) as a new series of random conjugated polymers (RCPs) bearing a large number of octyldodecyl chains to ensure solubility and a small number of thermocleavable tBoc function to cast H-bonding upon heating up to 220 C. All new polymers were synthesised via Pd catalysed Stille cross-coupling methodology in high yields and reasonable average molecular weights. The cast polymer films exhibited considerable red-shifted UV-vis absorption spectra and a further red-shift was also obtained in the thermal annealed films (at 220 C for 30 min), which reflected the increasing of crystalline structure. The formation of H-bonding in these polymers was investigated using X-ray diffractometry (XRD) measurements. The field-effect mobilities of these polymers were investigated in the configuration of bottom-gate and bottom-contact (BGBC) field-effect transistors (FETs). The results from FETs indicated that the crystalline structure of RCPs exhibited reasonable FET mobilities with 1.17 Â 10 À3 cm 2 V À1 s À1 for P(ODDPPT$BID) and 1.41 Â 10 À3 cm 2 V À1 s À1for P(ODDPPT$BDPP).