Ac impedance of frozen junction polymer light-emitting electrochemical cells

摘要

The structure of the frozen p-i-n junction in polymer light-emitting electrochemical cells (LECs) is studied by measurements of the a.c. impedance of LEC devices. Impedance plots of frozen junction LECs show characteristics that are typical of polymer Light-emitting diodes. The data demonstrate the 'freeze-out' of ionic mobility. The frequency-independent and voltage-independent capacitance of the frozen junction supports the conclusion that the insulating 'i' region in the p-i-n junction occupies most of the thickness of the LEC polymer layer. (C) 1998 Elsevier Science S.A. All rights reserved. [References: 20]