Huang Peng, Yuan Guodong, Wei Tongbo, Li Jinmin, Ashfold Michael N R
Research and Development Center for Solid State Lighting, Institute of Semiconductors, Chinese Academy of Sciences Beijing China
School of Chemistry, University of Bristol Bristol UK BS8 1TS
RSC Adv. 2018 Jun 6;8(37):20686-20691. doi: 10.1039/c8ra03359e. eCollection 2018 Jun 5.
The relative intensity of the blue component of the total emission from light-emitting diodes (LEDs) can be an important factor when assessing their biological safety. Carbon quantum dots (CQDs) are compatible with many materials and present a high density of multiple surface states; the incorporation of such CQDs thus offers a route to modifying the emission from a given LED matrix. Here we report the fabrication of stable CQD/zinc pyrovanadate (Zn(OH)VO·2HO) nanoplate composites a facile hydrothermal route. Structural and morphological analyses confirm that the nanoplates are hexagonal phase and grew normal to the [0001] direction. X-ray photoemission spectroscopy, Raman and infrared spectroscopy demonstrate that the CQDs combine with nanoplates surface carbon-oxygen bonds. Wavelength resolved photoluminescence measurements show that the relative intensity of the blue (2.93 eV) component of the emission associated with the nanoplates is significantly reduced by incorporating CQDs. We suggest that this reduction arises as a result of preferential trapping of the higher energy photoelectrons by surface defects on the CQDs.
在评估发光二极管（LED）的生物安全性时，LED总发射光中蓝色成分的相对强度可能是一个重要因素。碳量子点（CQD）能与多种材料兼容，且具有高密度的多个表面态；因此，掺入此类CQD为改变给定LED矩阵的发射光提供了一条途径。在此，我们报告了通过简便的水热法制备稳定的CQD/焦钒酸锌（Zn(OH)VO·2HO）纳米片复合材料。结构和形态分析证实，这些纳米片为六方相，且沿[0001]方向垂直生长。X射线光电子能谱、拉曼光谱和红外光谱表明，CQD与纳米片通过表面碳 - 氧键结合。波长分辨光致发光测量结果显示，掺入CQD后，与纳米片相关的发射光中蓝色（2.93 eV）成分的相对强度显著降低。我们认为，这种降低是由于CQD表面缺陷优先捕获了较高能量的光电子所致。
