In a new publication from Opto-Electronic Advances; DOI 10.29026/oea.2022.200075 , the research group of Professor Zhigang Zang from Chongqing University, Chongqing, China discusses realizing warm white light-emitting with high efficient emission and high color rendering index by using ligand modified CsPbBr3 quantum dots.
Nowadays, lighting accounts for approximately one-fifth of the global electricity consumption, which leads to a large increase in the emissions of carbon dioxide (CO2). To reduce the energy demand for lighting, solid-state white light-emitting diodes (WLEDs) are becoming the most promising illumination sources, which are much more efficient, energy savings and environmental friendliness than that of the traditional bulbs and fluorescent lighting sources. A common way of achieving a white light emission is composed of a near-UV or blue LEDs with a coating of either down-conversion materials (i.e. YAG:Ce3+ phosphors) or a combination of red and green phosphors. Unfortunately, such WLEDs suffer from poor white light performance after extensive use due to the different degradation rates between the blue LEDs and phosphors. In addition, they usually exhibit unsatisfactory high correlated color temperature (CCT) value and a low color rendering index (CRI 3 perovskite quantum dots (QDs) have been recognized as one of the most promising candidates for WLEDs due to the excellent optoelectronic properties.
The research group of Professor Zhigang Zang from Chongqing University presents a facile strategy to achieve excellent stability of CsPbBr3 QDs and high performance of WLEDs by using shorter 2-hexyldecanoic acid (DA) ligand to replace OA ligand for CsPbBr3 QDs. The ligand modified CsPbBr3 QDs exhibit a high PLQY of 96% with significantly enhanced stability, even when exposed to ethanol and water environments. Consequently, WLEDs by combining a blue InGaN LED with green ligand modified CsPbBr3 QDs and red AgInZnS QDs are achieved, which generate high quality warm white light emission
The WLEDs based on the modified CsPbBr3 QDs show a good thermal performance under high driving current, verifying their potential application in the field of solid-state lighting.
Article reference: Yan DD, Zhao SY, Zhang YB, Wang HX, Zang ZG. Highly efficient emission and high-CRI warm white light-emitting diodes from ligand-modified CsPbBr3 quantum dots. Opto-Electron Adv 5, 200075 (2022) . doi: 10.29026/oea.2022.200075
Keywords: CsPbBr3 quantum dots / ligand modification / stability / efficiency / white light-emitting diodes
