Colloidal Silicon Quantum Dot‐Based Cavity Light‐Emitting Diodes with Narrowed and Tunable Electroluminescence

Abstract

the alternatives, [7] Si is attractive because of its abundance, biocompatibility, [8] compatibility with silicon-based electronics, [9] luminescent properties when formed as QDs and established/tailorable surface chemistry. [10] EL of silicon-based nanomaterials (e.g., porous silicon, [11] Si nanocrystals in solid matrices [12] ) was first reported in the early 1990s and 2000s with low external quantum efficiencies (EQE) from 10 −6 to 1%. Of late, attention has shifted to colloidal silicon quantum dots (SiQDs) as potential active materials in hybrid organic light-emitting diodes (OLED) structures because of their promising EQE of up to 8.6% for near infrared (NIR) EL and 6.2% for red EL. [9a] Even with these improved metrics, the practical potential SiQD-LEDs remains limited by broad EL bandwidths with full-width-at-half-max-

Silicon quantum dots: surface matter, what next?

“…In contrast, Cheong et al (2022) 95 recently demonstrated that the electroluminescence of colloidal SiQD particles with narrow emission in the range of B100-23 nm at visible light wavelengths (yellow, orange, red to infrared) could be tuned without changing the dimensions of the SiQD particles. 95 Emission narrowing was achieved solely by adjusting the Fabry-Pe ´rot cavities, and the voltage applied. The results show that the visual and spectral stability is remarkable at different voltages.…”

“…There are many methods have been developed to produce hydrogen-terminated SiQDs. It is worth to mentions: silane gas plasma synthesis (SiH 4 ), 22,23,25,88,89 electrochemical etching, [90][91][92] halosilane reduction reaction, 93,94 oxide-rich silicon thermal synthesis, [53][54][55] hydrogen silsesquioxane thermal synthesis, 4,6,11,17,[29][30][31][32][33][34][35][36][37][39][40][41][42][43][44][45][46][47][48][49][50][51][52]95 tetraethoxysilane (TES) thermal synthesis, 96,97 pulsed laser ablation, and recently also the green synthesis of rice husk thermal pyrolysis. 85 In general, the photoluminescence of the resulting material depends on the type of synthesis carried out.…”

“…So it is very noticeable when we tune the particle size from f B 2.5 nm to f B 15 nm; PL-max is redshift gradually from l max 590 nm to l max 1100 nm. 4,6,11,12,17,[29][30][31][32][33][34][35][36][37][39][40][41][42][43][44][45][46][47][48][49][50][51][52][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71]77,95,[98][99][100][101][102][103]…”

“…The thickness of the SiO 2 and Ag layers in the device can be adjusted to optimize the emission according to the voltage used. 95…”

Nanocomposites of Silicon Oxides and Carbon: Its Study as Luminescent Nanomaterials

“…In addition to the PL emission, the PSi has been extensively studied due to its unique characteristics, such as its wide specific area in a small volume, pore size control, biocompatibility, and its compatibility with silicon manufacturing technologies [ 2 , 3 , 4 , 5 , 6 ]. There are numerous techniques for processing crystalline silicon and to obtain the Psi.…”