One-Pot Synthesis of InP Multishell Quantum Dots for Narrow-Bandwidth Light-Emitting Devices

Abstract

With tunable emission in the full visible region, the ecofriendly InP quantum dots (QDs) show unique application prospects in light-emitting devices. At present, InP QDs suffer from wide-bandwidth emission, especially for electroluminescence (EL), which hinders their applications in high-performance display devices. Here, we report a facile one-pot synthesis of narrow-bandwidth InP/ZnSeS/ZnS QDs using a safe phosphorus source of tris­(dimethylamino)­phosphine, in which the ZnSeS inner-shell layer is formed via temperature-gradient solution growth from 240 to 280 °C. The synthesized green QDs have a high photoluminescence quantum yield (PLQY) of 91% and full width at half-maximum (fwhm) of 36 nm. Moreover, the resultant quantum dot light-emitting devices (QLEDs) also show a narrow fwhm of 42 nm, which is the narrowest emission of green InP QLEDs based on a safe phosphorus source reported so far. Further modulation of the electron injection into the device by inserting a thin layer of lithium fluoride results in a peak external quantum efficiency of 5.56%.

Colloidal quantum dots as single photon sources

“…33 Given the ability to encompass a broad spectrum of emission wavelengths, spanning from the visible to the infrared, including those utilized in telecommunications, CQDs hold promise for diverse applications. [36][37][38][39][40] For example, varying the sizes of CdSe-based CQDs allows for tunability within the visible wavelength range, whereas the utilization of PbS-based CQDs can achieve emission in the near-infrared regions. (Fig.…”

Advancements in semiconductor quantum dots: expanding frontiers in optoelectronics, analytical sensing, biomedicine, and catalysis

“…Since then, a great deal of strategic work has been done to increase the PLQY as in these early stages of synthetic technique development, CQDs suffered from a range of surface defects, which acted as traps for excitons and reduced the PLQY. These methods include core–shelling, 87–92 alloying, 93 alloy-shelling, 94,95 addition of foreign solvent or substrate, 96 ligand exchange or passivation 97–100 and ligand cleavage 101 etc. as described in Table 1 along with external quantum efficiency (EQE).…”

“…10A), resulting in a peak external quantum efficiency (EQE) of 5.56%. 87 In another work, a quasi-shell-growth strategy (QS strategy) was applied to InP CQDs to form InP/ZnSe/ZnS CQDs for QLEDs. The PLQY of these CQDs was found to exceed 90% with a narrow emission linewidth of 36 nm.…”