Organic Light Emitting Diodes Using Doped Alq3 as the Hole-transport Layer
LIANG Chun-Jun1, WANG Yang2, YI Li-Xin1
1Key Laboratory of Luminescence and Optical Information (Ministry of Education), Beijing Jiaotong University, Beijing 1000442Key Laboratory of Opto-Electronic Technology and Intelligent Control (Ministry of Education), Lanzhou Jiaotong University, Lanzhou 730070
Organic Light Emitting Diodes Using Doped Alq3 as the Hole-transport Layer
LIANG Chun-Jun1, WANG Yang2;YI Li-Xin1
1Key Laboratory of Luminescence and Optical Information (Ministry of Education), Beijing Jiaotong University, Beijing 1000442Key Laboratory of Opto-Electronic Technology and Intelligent Control (Ministry of Education), Lanzhou Jiaotong University, Lanzhou 730070
摘要Effects of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) doping on the hole conductivity of Alq3 layer are measured. In the hole-only device of Alq3, the current densities increase in 1--3 orders of magnitude upon doping with F4TCNQ, suggesting that the doping can effectively enhance the hole-injection and hole-transport ability of Alq3. An organic light-emitting device using an F4TCNQ doped Alq3 layer as the hole-injection and hole-transport layer, and pristine Alq3 as the electron-transport and emitting layer is fabricated and characterized. Bright emission is achieved in the simple OLED with p-doped Alq3 as the hole-transport layer and the intrinsic Alq3 as the electron-transport and emitting layer. The emitting efficiency and brightness of the device are further improved by inserting a thin electron block layer to confine the carrier recombination zone in the middle of the organic layers.
Abstract：Effects of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) doping on the hole conductivity of Alq3 layer are measured. In the hole-only device of Alq3, the current densities increase in 1--3 orders of magnitude upon doping with F4TCNQ, suggesting that the doping can effectively enhance the hole-injection and hole-transport ability of Alq3. An organic light-emitting device using an F4TCNQ doped Alq3 layer as the hole-injection and hole-transport layer, and pristine Alq3 as the electron-transport and emitting layer is fabricated and characterized. Bright emission is achieved in the simple OLED with p-doped Alq3 as the hole-transport layer and the intrinsic Alq3 as the electron-transport and emitting layer. The emitting efficiency and brightness of the device are further improved by inserting a thin electron block layer to confine the carrier recombination zone in the middle of the organic layers.
[1] Tang C W and Vanslyke S A 1987 Appl. Phys. Lett. 51 913 [2] Tang C W 1986 Appl. Phys. Lett. 48 183 [3] Blochwitz J, Pfeiffer M, Fritz T and Leo K 1998 Appl. Phys. Lett. 73 729 [4] Zhou X, Pfeiffer M, Blochwitz J, Werner A, Nollau A, Fritz T andLeo K 2001 Appl. Phys. Lett. 78 410 [5] Maennig B, Drechsel J, Gebeyehu D, Simon P, Kozlowski F, Werner A,Li F, Grundmann S, Sonntag S, Koch M, Leo K, Pfeiffer M, Hoppe H,Meissner D, Sariciftci N S, Riedel I, Dyakonov V and Parisi J 2004 Appl. Phys. A 79 1 [6] Pfeiffer M, Beyer A, Fritz T and Leo K 1998 Appl. Phys.Lett. 73 3202 [7] Gao W and Kahn A 2001 Appl. Phys. Lett. 79 4040 [8] Ding H J and Gao Y L 2005 Appl. Phys. Lett. 86 213508 [9] Ganzorig C, Suga K and Fujihira M 2001 Mater. Sci. Eng. B 85 140 [10] Parthasarathy G, Shen C, Kahn A and Forrest S R 2001 J. Appl.Phys. 89 4986 [11] Kido J and Matsumoto T 1998 Appl. Phys. Lett. 73 2866 [12] Hung L S, Zhang R Q, He P and Mason G 2002 J. Phys. D: Appl.Phys. 35 103 [13] Mason M G, Tang C W, Hung L S, Raychaudhuri P, Madathil J, GiesenD J, Yan Y, Le Q T, Gao Y, Lee S T, Liao L S, Cheng L F, Salaneck W R,Santos D A and Bre'das J L 2001 J. Appl. Phys. 89 2756 [14] Le Q T, Yan L, Gao Y, Mason M G, Giesen D J, and Tang C W 2000 J.Appl. Phys. 87 375
2008, Vol. 25 
