Efficient All‐Perovskite White Light‐Emitting Diodes Made of In Situ Grown Perovskite‐Mesoporous Silica Nanocomposites

Abstract

Metal halide perovskite quantum dots (QDs) have emerged as potential materials for high brightness, wide color gamut, and cost‐effective backlight emission due to their high photoluminescence quantum yields, narrow emission linewidths, and tunable bandgaps. Herein, CsPbX3/SBA‐15 nanocomposites are prepared with outstanding optical properties and high stability through an in situ growth strategy using mesoporous silica particles. According to finite‐difference time‐domain simulations, the mesoporous structure provides a strong waveguide effect on perovskite QDs and the uniform dispersion suppresses reabsorption losses, improving the overall photoconversion efficiency of perovskite QDs. The as‐fabricated perovskite monochromatic light‐emitting diode (LED) has a maximum luminous efficiency of 183 lm W−1, which is the highest for monochromatic perovskite LEDs reported to date. A further benefit of this work is that the white devices, which combine the green and red perovskite nanocomposites with commercial blue LED, exhibit a high luminous efficiency of 116 lm W−1 and a wide color gamut (125% for NTSC and 94% for Rec. 2020) with coordinates of (0.33,0.31).

A thermally induced fluorescence enhancement strategy for efficient all-inorganic rubidium manganese halide

“…2d), which is ascribed to the d-d transition of Mn 2+ . 33 Among them, the excitation peaks at 262 nm, 273 nm, 287 nm, 344 nm, 363 nm, 380 nm, 435 nm, 452 nm, and 530 nm are assigned to the electronic transitions from the ground state 6 A 1 ( 6 S) to the excited states 4 T 2 ( 4 F), 4 T 1 ( 4 F), 4 A 2 ( 4 F), 4 T 1 ( 4 P), 4 4 T 2 ( 4 G) and 4 T 1 ( 4 G), respectively.…”

“…[1][2][3] In particular, combining green and red emissive lead-based metal halides with blue chips for the fabrication of white LED (WLED) devices has made tremendous progress, which achieved a wide color gamut (above 125% of the National Television System Commission) and a high luminous efficacy (LE) of 116 lm W −1 . 4,5 Considering the intrinsic instability and toxicity of lead-based metal halides in practical applications, many efforts have been devoted to exploring environmentally friendly metal halides with outstanding properties. 6,7 Owing to structural diversity and rich elements, metal halides based on Sn 2+ , 8,9 Bi 3+ , 10,11 Sb 3+ , 12,13 In 3+ , 14,15 Cu + , 16,17 and Ag + /In 3+ ions 18 are regarded as ideal alternatives due to the attractive features of self-trapped excitons.…”

Ultrastable CsPbBr3@CsPb2Br5@TiO2 Composites for Photocatalytic and White Light-Emitting Diodes

“…There were three main directions: (1) construction of core–shell structures, (2) modification of surfaces using ligands, and (3) packaging by polymers. Among them, core–shell-structured perovskite QDs were an important class of nanomaterials, which not only used stable substances as protective shells to directly isolate QDs from PL quenching molecules, but also formed heterojunctions at interfaces, providing a platform for exploring completely new photophysical properties. − …”

Uniform nucleation and growth of Cs3Cu2I5nanocrystals with high luminous efficiency and structural stability and their application in white light-emitting diodes

“…Lead halide perovskite nanocrystals (NCs) have been widely used in the field of light-emitting diodes (LEDs) due to their outstanding optoelectronic properties such as tunable emission wavelengths, high photoluminescence quantum yields (PLQYs), and narrow emission line widths. [1][2][3][4][5][6][7][8][9][10][11][12][13] To date, the external quantum efficiencies (EQEs) of perovskite-based LEDs have exceeded over 20%, showing great potential in next-generation displays and lighting. [14][15][16][17][18][19][20] However, their intrinsic heavy-metal toxicity and instability seriously restrict their practical application.…”