中国物理B ›› 2020, Vol. 29 ›› Issue (12): 128503-.doi: 10.1088/1674-1056/abc154

• • 上一篇    下一篇

  

  • 收稿日期:2020-08-04 修回日期:2020-09-08 接受日期:2020-10-15 出版日期:2020-12-01 发布日期:2020-11-19

Reliability of organic light-emitting diodes in low-temperature environment

Saihu Pan(潘赛虎)1, Zhiqiang Zhu(朱志强)1, Kangping Liu(刘康平)2, Hang Yu(于航)1, Yingjie Liao(廖英杰)2, Bin Wei(魏斌)2, Redouane Borsali3, and Kunping Guo(郭坤平)2,4,†   

  1. 1 School of Microelectronics and Control Engineering, Changzhou University, Changzhou 213164, China; 2 School of Mechatronic Engineering and Automation, Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China; 3 Universdity of Grenoble Alpes, CNRS, CERMAV, F-38000 Grenoble, France; 4 London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
  • Received:2020-08-04 Revised:2020-09-08 Accepted:2020-10-15 Online:2020-12-01 Published:2020-11-19
  • Contact: Corresponding author. E-mail: gkp@shu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61775130 and 11974236), the Science and Technology Commission of Shanghai Municipality Program, China (Grant Nos. 19DZ2281000 and 17DZ2281000), and the Research Innovation Program for College Graduates of Jiangsu Province, China (Grant Nos. KYCX20_2545 and KYCX20_2549).

Abstract: Organic light-emitting diode (OLED) is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions. Here, by exploiting a self-developed low-temperature testing system, we investigated the characteristics of hole/electron transport, electro-optic conversion efficiency, and operation lifetime of OLEDs at low-temperature ranging from -40 °C to 0 °C and room temperature (25 °C). Compared to devices operating at room temperature, the carrier transport capability is significantly decreased with reducing temperature, and especially the mobility of the hole-transporting material (HTM) and electron-transporting material (ETM) at -40 °C decreases from 1.16× 10-6 cm2/Vs and 2.60× 10-4 cm2/Vs to 6.91× 10-9 cm2/Vs and 1.44× 10-5 cm2/Vs, respectively. Indeed, the temperature affects differently on the mobilities of HTM and ETM, which favors unbalanced charge-carrier transport and recombination in OLEDs, thereby leading to the maximum current efficiency decreased from 6.46 cdA-1 at 25 °C to 2.74 cdA-1 at -40 °C. In addition, blue fluorescent OLED at -20 °C has an above 56% lifetime improvement (time to 80% of the initial luminance) over the reference device at room temperature, which is attributed to efficiently dissipating heat generated inside the device by the low-temperature environment.

Key words: organic light-emitting diodes (OLEDs), low temperature, reliability, operation lifetime

中图分类号:  (Light-emitting devices)

  • 85.60.Jb
78.60.Fi (Electroluminescence) 07.20.Mc (Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment) 81.40.Rs (Electrical and magnetic properties related to treatment conditions)