Improved Luminous Efficiency of AgInS₂ Quantum Dots and Zeolitic Imidazolate Framework‐70 Composite for White Light Emitting Diode Applications

Abstract

The application of multiple quantum dots (QDs) in the field of white light emitting diodes (WLEDs) is still an important challenge due to their low luminous efficiency and quenching phenomenon. In this paper, we prepared AgInS2 QDs/zeolitic imidazolate framework‐70 (AIS/ZIF‐70) composite by a microwave hydrothermal method. Owing to the high porosity and stability of ZIF‐70, it could effectively prevent quenching issues due to the aggregation of QDs. Since the ZIF‐70 and QDs were chemically bonded, the formation of the ZnS layer could effectively passivate the surface defect and thus the quantum yield reached 21.49 % in aqueous solution. The luminous efficiency (LE) of the assembled AIS/ZIF‐based WLED was reinforced by 6.8 times with a molar ratio of AgIn/Zn=18, i. e. at 5.26 % molar fraction of ZIF‐70. Moreover, the color rendering index (CRI) and correlated color temperature (CCT) of AIS/ZIF‐based WLED were 84.3 and 3631 K, respectively, indicating its potential application in solid‐state lighting.

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

“…Two common approaches to producing white light from CQDs stem from either mixing a set of quantum dot films of different emission colours, 114 or by the specific synthesis of nanocrystals with a wide luminescence band. 115 To achieve a broad luminescence peak, purpose trap-related emission can be stimulated via surface passivation 116 or modification 117 or nanocrystals can be doped with specific ions such as Cu + and Mn 2+ . 118 Another emerging technique utilizes the integration of CQDs on different color LED chips.…”