PEDOT:PSS polymeric conducting anode for admittance spectroscopy

• Published in: Organic electronics Vol. 7; no. 6; pp. 474 - 479
• Main Authors: Tsang, S.W., Tse, S.C., Tong, K.L., So, S.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2006; Elsevier
• Subjects: Admittance spectroscopy; Applied sciences; Carrier mobility; Carrier transport; Electronics; Exact sciences and technology; Injection; Materials; Ohmic contact; PEDOT; Susceptance; Ohmic contact; PEDOT; 73.61.Ph; Admittance spectroscopy; Injection; Susceptance; Carrier mobility; Carrier transport; Molecular orbital; Anode; Charge carrier mobility; Hole mobility; Sandwich structure; Doped materials; Electrode material; Transport process; Spectrometry; Thiophene derivative polymer; Time of flight method; Organic electronics
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2006.06.002

The carrier mobilities of two hole transporting organic materials were evaluated by admittance spectroscopy (AS). The materials were 4,4′,4″-tris{ N,-(3-methylphenyl)- N-phenylamino}triphenylamine ( m-MTDATA) and N, N ′-diphenyl- N, N′-bis(1,1′-biphenyl)-4,4′-diamine (NPB). They were sandwiched in a configuration of anode/organic material/cathode. The anode was either indium-tin-oxide (ITO) or poly(3,4-ethylenedioxythiophene) doped with polystrenesulphonic acid (PEDOT:PSS). It is shown that PEDOT:PSS can, respectively, form Ohmic and quasi-Ohmic contact with m-MTDATA and NPB. Using PEDOT:PSS as the anode, the average hole mobilities of m-MTDATA and NPB were extracted by AS through susceptance analysis. The results are in excellent agreement with those obtained by an independent time-of-flight (TOF) technique. With PEDOT:PSS, the application of AS for characterizing carrier mobilities can be extended to hole transporting organic materials with highest occupied molecular orbital (HOMO) energy levels down to 5.4 eV.