Effect of dye concentration on the charge carrier transport in molecularly doped organic light-emitting diodes
Effect of dye concentration on the charge carrier transport in molecularly doped organic light-emitting diodes
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DOI：
10.1063/1.1703834
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发表时间：
2004-05-15
影响因子：
3.2
通讯作者：
Ma, DG
中科院分区：
文献类型：
--
作者：
Chen, JS;Ma, DG
通过稳态电流-电压特性和瞬态电致发光的测量，研究了掺杂剂4-（二氰基亚甲基）-2-叔丁基-6-（1，1，7，7-四甲基久洛尼啶基-9-烯基）-4H-吡喃（DCJTB）在三（8-羟基喹啉）铝（Alq（3））中的浓度对Alq（3）：DCJTB中载流子输运的影响。电流-电压关系的掺杂剂浓度依赖性清楚地表明DCJTB分子的载流子捕获。DCJTB浓度显著影响Alq（3）：DCJTB中的电子迁移率。的迁移率有一个不平凡的依赖于掺杂水平。对于相对低的掺杂水平，小于1%，Alq（3）：DCJTB的电子迁移率随掺杂水平而降低。如果掺杂浓度进一步增加，则观察到增加的迁移率，随后对于大于类似于2%的掺杂水平降低。Alq（3）中电子迁移率随DCJTB浓度的变化归因于在相对低的掺杂浓度下由随机分布的掺杂剂的偶极-偶极相互作用引起的电势涨落引起的额外的能量无序，以及在高掺杂浓度下的相分离。(C)2004年，美国物理学会。
The effect of the concentration of 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as dopant in tris(8-quinolinolato) aluminum (Alq(3)) on the charge carrier transport in Alq(3):DCJTB was investigated by measuring the steady current-voltage characteristics and the transient electroluminescence. The dopant concentration dependence of the current-voltage relationship clearly indicates the carrier trapping by the DCJTB molecule. The DCJTB concentration significantly affects the electron mobility in Alq(3):DCJTB. The mobility has a nontrivial dependence on the doping level. For relatively low doping levels, less than 1%, the electron mobility of Alq(3):DCJTB decreases with the doping level. An increasing mobility is then observed if the dopant concentration is further increased, followed by a decrease for doping levels larger than similar to2%. The change of the electron mobility with the DCJTB concentration in Alq(3) is attributed to the additional energetic disorder due to potential fluctuations caused by the dipole-dipole interaction of random distribution dopant at the relatively low doping concentration, and to the phase separation at the high doping concentration. (C) 2004 American Institute of Physics.