Enhanced Optical and Electrical Properties of Polymer‐Assisted All‐Inorganic Perovskites for Light‐Emitting Diodes

Abstract

Highly bright light-emitting diodes based on solution-processed all-inorganic perovskite thin film are demonstrated. The cesium lead bromide (CsPbBr ) created using a new poly(ethylene oxide)-additive spin-coating method exhibits photoluminescence quantum yield up to 60% and excellent uniformity of electrical current distribution. Using the smooth CsPbBr films as emitting layers, green perovskite-based light-emitting diodes (PeLEDs) exhibit electroluminescent brightness and efficiency above 53 000 cd m and 4%: a new benchmark of device performance for all-inorganic PeLEDs.

Highly Luminescent Lead Halide Perovskite Quantum Dots in Hierarchical CaF2 Matrices with Enhanced Stability as Phosphors for White Light‐Emitting Diodes

“…It can be seen from the spectrum of the resulting device (Figure 4a), three discrete emission peaks located at 442, 520, and 621 nm were observed. And the as-prepared composites [28,36,37,40,42,46,47,51,53] could act as the green phosphors with decent performance. The selected triangle of blue, green, and red monochromatic light covers 130% of the National Television System Committee (NTSC) standard, which indicates great potential application in white backlights for LCDs.…”

“…[7] Colloidal quantum dots (QDs) such as CdSe, [8,9] InP, [10] and PbS [11] have been regarded as a new class of luminescent materials due to their high chemical stability, high PL QY, and tunable emission wavelengths which can easily cover the whole visible region by varying their size or dimension. [22][23][24][25][26][27][28][29] Despite these advantages of PQDs, the intrinsic instability and poor durability of the perovskite severely hamper the practical applications, which causes a huge technical obstacle for commercialization. [12][13][14][15][16][17][18][19][20][21] The high quantum efficiency, high color purity, and facile preparation make them as promising candidates for LED or backlight downconverters for LCDs.…”

Emergence of Nanoplatelet Light-Emitting Diodes

“…In addition, since all-inorganic perovskites can show narrow emission (e.g., FWHM < 20 nm) and excellent PLQY (e.g., ~100% in solution), they have triggered great interest to develop LEDs [132,133,134,135,136]. After the first LED with all-inorganic perovskites developed in 2015 [137], many methods were used to enhance the performance of this kind of LEDs based on 3D nanocubes [138,139,140]. For 2D all-inorganic perovskite NPLs, Bekenstein et al first reported CsPbX 3 NPLs showing the 1–5 unit cells thickness in 2015 [141].…”

Ultra-bright and highly efficient inorganic based perovskite light-emitting diodes

“…and Ling et al . both reported inorganic CsPbBr 3 LEDs with about 6% EQE by surface passivation of perovskite nanocrystals and controlling perovskite thin film morphology, respectively3536. There is still much more room for improvement in brightness and efficiency.…”