Realization of Narrow‐Bandwidth Cu‐Ga‐S‐Based Quantum Dots with Controllable Luminescence

Abstract

Recently, I‐III‐VI type quantum dots (QDs) have attracted considerable attention in display technology due to their large‐scale tunable emission and environmentally friendly characteristics. However, within this family, narrow‐bandwidth Cu‐based QDs have rarely been reported. Herein, the synthesis of narrow‐bandwidth blue‐emitting Cu‐Ga‐S (CGS)‐based QDs is reported by a hot‐injection method for the first time, boasting a narrow full width at half‐maximum (FWHM) of 29 nm, closely approaching that of traditional Cd‐based QDs. Through precisely controlling the temperature of nucleation stage, CGS‐based QDs showcase a representative blue emission at 475 nm, featuring the narrowest FWHM and a photoluminescence quantum yield (PLQY) of 32%. Besides, the femtosecond transient fluorescence (fs‐TA) characterization indicates that the narrow‐bandwidth luminescence is attributed to band‐to‐hole recombination rather than donor‐acceptor pair (DAP) recombination. The work opens a new avenue for narrow‐bandwidth I‐III‐VI QDs, offering increased potential for applications in blue‐light‐emitting devices.

One-Pot Synthesis of Color-Tunable Narrow-Bandwidth Ag–In–Ga–Zn–S Semiconductor Nanocrystals for Quantum-Dot Light-Emitting Diodes

“…These results indicate that the Ga ion is more likely to diffuse into the interior of AIGZS NCs, thus passivating interior defects and producing more Ag vacancies. The increase of Ag vacancies has been shown to benefit the band-to-hole emission, resulting in narrow-bandwidth emission. ,, Hence, all of these results indicate that the proper regulation of the In/Ga ratios and the presence of Zn are crucial for achieving color-tunable narrow-bandwidth AIGZS NCs.…”