关键词: 量子点/
MEH-PPV/
白光/
掺杂
English Abstract
White light emitting diode based on quantum dots and MEH-PPV
Sun Li-Zhi,Zhao Su-Ling,
Xu Zheng,
Yin Hui-Li,
Zhang Cheng-Wen,
Long Zhi-Juan,
Hong Xiao-Xia,
Wang Peng,
Xu Xu-Rong
1.Institute of Optoelectronics Technology, Beijing Jiaotong University, Key Laboratory of Luminescence and Optical Information (Beijing Jiaotong University), Ministry of Education, Beijing 100044, China
Fund Project:Project supported by the National High Technology Research and Development Program of China (Grant No. 2013AA032205), the National Natural Science Foundation of China (Grant Nos. 11474018, 51272022, 61575019), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No 20120009130005, 20130009130001), and the Technological Development Contract (csot) (Grant No. HETONG-150188-04E008).Received Date:16 November 2015
Accepted Date:22 December 2015
Published Online:05 March 2016
Abstract:The white light emitting diode (LED) devices, in which blue-emitting quantum dots doped in the polymer of poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylene vinylene] (MEH-PPV) serve as the active layer, have been fabricated in a nitrogen-filled glove box; the devices have the structure of ITO/PEDOT/MEH-PPV:QDs(B)/LiF/Al. After a systematical investigation, we report the effect of different quantum dots (QDs) doping concentration (mass fraction) on the electroluminescent spectrum, current density, brightness, CIE coordinates of the devices and atomic force microscopy (AFM) characterizations of the emitting layer. With the increase of QDs doping concentration, we find that the QDs luminance intensity of the controlling devices continues to grow. When the QDs doping concentration is 40%, the normal white light emission is obtained in the devices. The CIE coordinates of the white QD-LED are (0.35, 0.32), which are close to the balanced white coordinates. Besides, we also fabricate the non-doped devices, in which the structure is ITO/PEDOT/MEH-PPV/QDs(B)/LiF/Al. After finishing the active layer's preparation, the morphology of the films are investigated by AFM. By comparing the analysis, the doped system has a lower level on the root mean squared roughness. In addition, the doped devices demonstrate a superior performance, and exhibit a low turn-on voltage and a high maximum value of luminance.
Keywords: quantum dots/
MEH-PPV/
white light/
dope
