High-Performance Pure Red Quasi-Two-Dimensional Perovskite Light-Emitting Diodes with Bifunctional Potassium Trifluoroacetate Additive

Abstract

Solution-processed pure iodide-based quasi-twodimensional (quasi-2D) perovskites exhibit tremendous potential for pure red light-emitting diodes, required for a wide color gamut display. However, the nonradiative recombination derived from the numerous defects and broad phase distribution restricts the performance of quasi-2D perovskite light-emitting diodes (PeLEDs). Herein, we demonstrate highperformance pure red quasi-2D PeLEDs by introducing a bifunctional potassium trifluoroacetate (KTFA) additive that simultaneously passivates the defects and regulates phase distribution. The KTFA-modified PeLEDs achieve a peak external quantum efficiency of 18.70%, a maximum luminance of 2377.1 cd m −2 , and an electroluminescence (EL) emission peak at 650 nm with a CIE coordinate of (0.705,0.295) approaching the pure red emission of Rec.2020 standard. Moreover, our devices demonstrate a stable EL spectrum and a half-lifetime (T 50 ) of 476 min at an initial luminance of 100 cd m −2 . Our work provides a viable strategy to boost the performance of quasi-2D PeLEDs.

Two-dimensional complex metal halides: influence of restricted dimensionality on functional properties

“…109 Since 2016, extensive research efforts have been dedicated to investigating RP phases with varied color emissions for LED applications. These include studies on red emissions, [110][111][112] green emissions, 93,113 and blue emissions. [114][115][116] Blue RP phase emitters, however, lag behind their red and green counterpart mainly due to increased electron-phonon coupling and trap-mediated non-radiative recombination, less efficient energy transfer, and interface uorescence quenching.…”

Chirality Extends Multiple-Channel Bistable Responses in Hybrid Perovskites

“…Organic–inorganic hybrid materials can provide a good platform for achieving material versatility due to synchronously and complementary characteristics of organic components and various inorganic frameworks. − Many effective strategies (halogen engineering, − dimensional regulation, introducing specific functional groups, , homochirality induction, − etc.) have been proposed and validated to improve material properties during the exploration of materials.…”

High Efficiency and Low Roll-Off Pure-Red Perovskite LED Enabled by Simultaneously Inhibiting Auger and Trap Recombination of Quantum Dots

“…The average EQE based on 15 devices is 22.0% (Figure e). Furthermore, the low efficiency roll-off of the device demonstrates the suppression of Auger recombination. , When the brightness is increased to 1017 cd m –2 , the EQE of the LED can still be maintained at 18.0%, which is more than the majority of pure-red perovskite LEDs. ,− ,− The EL peak of the LED is 639 nm with a narrow fwhm of 34 nm (Figure f). In the process of gradually increasing the bias voltage, the EL spectrum peak of the LED can maintain no shift, indicating excellent spectral stability.…”