Light-Converting Polymer/Si Nanocrystal Composites with Stable 60–70% Quantum Efficiency and Their Glass Laminates

Abstract

Thiol-ene polymer/Si nanocrystal bulk hybrids were synthesized from alkyl-passivated Si nanocrystal (Si NC) toluene solutions. Radicals in the polymer provided a copassivation of "dark" Si NCs, making them optically active and leading to a substantial ensemble quantum yield increase. Optical stability over several months was confirmed. The presented materials exhibit the highest photoluminescence quantum yield (∼65%) of any solid-state Si NC hybrid reported to date. The broad tunability of thiol-ene polymer reactivity provides facile glass integration, as demonstrated by a laminated structure. This, together with extremely fast polymerization, makes the demonstrated hybrid material a promising candidate for light converting applications.

Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

“…Considering AQYs of HWA-SiNCs, our values match the highest reported ones, in the 50-60% range [2,7,9,10,17,19]. Most highly efficient SiNCs were obtained using organic surface passivation [2,9,10,17,19].…”

“…Luminescent Si nanocrystals (SiNCs) are intensively studied for their potential applications in diverse fields, such as optoelectronics, sensing, and medicine [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Some particularly important characteristics of such SiNCs include absolute quantum yield (AQY), stability, luminescence lifetime, surface chemistry, and synthesis route.…”

“…AQYs much greater than those obtained with PSi were reported recently. Focusing on ensemble AQYs above ∼40%, SiNCs mostly consisted of Si cores whose surface was terminated by various kinds of organic compounds, alkyl groups attached by hydrosilylation being the most typical [2,9,10,17,19,20]. The confinement somewhat depends on the type of organic group attached to the surface [20].…”

Photoluminescence Intensity Enhancement of Single Silicon Quantum Dots on a Metal Membrane with a Spacer

“…Thus, compared with bulk silicon, Si QDs possess a manifold of optical advantages, such as high PL quantum efficiencies, narrow emission linewidths, wavelength‐tunable PLs, and large Stokes shifts. Given also the abundance and nontoxicity of silicon, silicon nanocrystals are considered promising candidates for different light‐converting applications, such as in quantum‐dot‐based light‐emitting diodes (LEDs) and luminescent solar concentrators (LSCs) …”

“…Given also the abundance and nontoxicity of silicon, silicon nanocrystals are considered promising candidates for different light-converting applications, such as in quantum-dot-based light-emitting diodes (LEDs) and luminescent solar concentrators (LSCs). [4][5][6][7] Due to the rapid development of optical characterization techniques, single QDs can be routinely accessed now. Since being first introduced in the 1990s, [8,9] single-dot measurement has been commonly considered an effective way to provide a deeper insight into the intrinsic nature of nanocrystals by focusing on individual nanoparticles' behavior, instead of observing average statistics of ensembles.…”