Disentangling Bulk and Interface Phenomena in a Molecularly Doped Polymer Semiconductor
Disentangling Bulk and Interface Phenomena in a Molecularly Doped Polymer Semiconductor
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DOI：
10.1002/adom.202002039
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发表时间：
2021-02-02
影响因子：
9
通讯作者：
Koch, Norbert
中科院分区：
文献类型：
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作者：
Lungwitz, Dominique;Schultz, Thorsten;Koch, Norbert
掺杂电子传输聚合物聚{[N，N '-双（2-辛基十二烷基）萘-1，4，5，8-双（二甲酰亚胺）-2，6-二基]-alt-5，5 ′-（2，2 ′-联噻吩）} [P（NDI 2 OD-T-2）]与大体积强还原性茂金属1，2，3，4，1 ′，2 ′，3 ′，4 ′-八苯基罗二烯（OPR）的反应导致体积电导率增加和接触电阻降低。虽然前者是由本征聚合物的低水平n掺杂和由于陷阱填充而增加的载流子迁移率引起的，但后者是由掺杂剂分子在氧化铟锡（ITO）衬底处的显著积累引起的。从OPR到ITO的电子转移导致功函数降低，这将费米能级钉扎在P（NDI 2 OD-T-2）导带处，从而使电子注入势垒和接触电阻最小化。结果表明，解开掺杂剂和本体掺杂的电极修饰的影响是必不可少的，以全面了解掺杂的有机半导体。
Doping the electron-transport polymer poly{[N,N '-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5 '-(2,2 '-bithiophene)} [P(NDI2OD-T-2)] with the bulky, strongly reducing metallocene 1,2,3,4,1 ',2 ',3 ',4 '-octaphenylrhodocene (OPR) leads to an increased bulk conductivity and a decreased contact resistance. While the former arises from low-level n-doping of the intrinsic polymer and increased carrier mobility due to trap-filling, the latter arises from a pronounced accumulation of dopant molecules at an indium tin oxide (ITO) substrate. Electron transfer from OPR to ITO leads to a work function reduction, which pins the Fermi level at the P(NDI2OD-T-2) conduction band and thus minimizes the electron injection barrier and the contact resistance. The results demonstrate that disentangling the effects of electrode modification by the dopant and bulk doping is essential to comprehensively understand doped organic semiconductors.