Additive-Stabilized Emission Centers for Blue Perovskite Light-Emitting Diodes

Abstract

The performance of the blue perovskite light-emitting diodes (PeLEDs) is limited by the low photoluminescence quantum yields (PLQYs) and the unstable emission centers. In this work, we incorporate sodium bromide and acesulfame potassium into a quasi-2D perovskite to control the dimension distribution and promote the PLQYs. Benefiting from the efficient energy cascade channel and passivation, the sky-blue PeLED has an external quantum efficiency of 9.7% and no shift of the electroluminescence center under operation voltages from 4 to 8 V. Moreover, the half lifetime of the devices reaches 325 s, 3.3 times that of control devices without additives. This work provides new insights into enhancing the performance of blue PeLEDs.

Cyanuric Acid-Functionalized Perovskite Nanocrystals toward Low Interface Impedance, High Environmental Stability, and Superior Electrochemiluminescence

“…There is an ever-increasing research interest in light-emitting perovskite nanocrystals (PNs) due to the enormous advantages of such novel materials, e.g., high photoluminescence quantum yield (PLQY), 1 extremely narrow full width at half-maximum (FWHM) for superb color purity, 2,3 and color adjustability in a wide range. 4,5 Among various application fields of PNs, great attention has focused on developing high-performance PNbased light-emitting diodes (LEDs), in which high-quality PNs are used as the emissive layer (EML) of LEDs.…”

“…There is an ever-increasing research interest in light-emitting perovskite nanocrystals (PNs) due to the enormous advantages of such novel materials, e.g., high photoluminescence quantum yield (PLQY), extremely narrow full width at half-maximum (FWHM) for superb color purity, , and color adjustability in a wide range. , Among various application fields of PNs, great attention has focused on developing high-performance PN-based light-emitting diodes (LEDs), in which high-quality PNs are used as the emissive layer (EML) of LEDs. After combining chemical and physical strategies toward ideal PN-involved EML, a distinct process has been made in PN-based LEDs. − Among them, it is obvious in that one prevailing strategy lies in controlling of defect states on the surface of PNs. − Surface modification engineering is thus recognized as an effective approach to idealize the performance of PNs. − …”

Improving performance of sky-blue perovskite light-emitting diodes by triple additives

“…Due to their excellent photoelectric properties, metal halide perovskites have great potential in displays and lighting applications. [1][2][3][4][5] In the past few years, tremendous progress has been made in developing efficient perovskite light-emitting diodes (PeLEDs). Green, red, and near-infrared PeLEDs with external quantum efficiency (EQE) exceeding 20% have been reported.…”

“…23,25,26 To overcome such hurdles, adding alkali metal halides to the precursor solution can effectively modulate the crystallization dynamics to improve crystallinity and provide a halide-rich environment to passivate the halide vacancy defects. 16,27 Another class of effective additives in the perovskites to passivate the defects, confine the charge, and enhance the emission are long-chain organic ammonium salts, 28 such as PEABr, 1,18,29 p-F-PEABr, 20,23 and PBABr. 30 On the one hand, long-chain organic ammonium salts offer a halide-rich environment to passivate the halide vacancy defects, thereby improving the optical properties.…”

“…Another class of effective additives in the perovskites to passivate the defects, confine the charge, and enhance the emission are long-chain organic ammonium salts, 28 such as PEABr, 1,18,29 p-F-PEABr, 20,23 and PBABr. 30 On the one hand, long-chain organic ammonium salts offer a halide-rich environment to passivate the halide vacancy defects, thereby improving the optical properties.…”