Facile tailoring of the electrical transport in representative hole transport materials by molecular doping

Bixin Li; Chenyang Zhao; Shiyang Zhang; Min Zhen

doi:10.1039/c8ra03707h

Facile tailoring of the electrical transport in representative hole transport materials by molecular doping

RSC Adv. 2018 Jul 23;8(46):26230-26236. doi: 10.1039/c8ra03707h. eCollection 2018 Jul 19.

Authors

Bixin Li¹, Chenyang Zhao², Shiyang Zhang¹, Min Zhen¹

Affiliations

¹ Department of Science Education, Laboratory of College Physics, Hunan First Normal University Changsha 410205 People's Republic of China lbxin86@hotmail.com.
² State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, University of Chinese Academy of Sciences Changchun 130022 People's Republic of China.

Abstract

N,N'-Diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) and 4,4',4''-tris (N-3-methylphenyl-N-phenylamine) triphenylamine (m-MTDATA) are widely used as hole transport materials in organic optoelectronic devices. In the present article, the hole transport properties of blends of NPB and m-MTDATA compared with the pristine materials are investigated using admittance spectroscopy and considering temperature dependent current-voltage characteristics and electroluminescent characteristics. It has been found that m-MTDATA dramatically lowers the carrier mobility in the NPB matrix to a large extent by enhancing the total density of traps and results in more dispersive transport. However, by introducing NPB into m-MTDATA the hole mobility is nearly unchanged in comparison with pristine m-MTDATA film. These differences are attributed to two different charge transport mechanisms, trapping and scattering. Obtained quantitative information regarding the charge transport parameters could help to extend optimization strategies for the fabrication of new organic optoelectronic devices by enabling the facile tailoring of the charge transport process.