On the validity of MIS-CELIV for mobility determination in organic thin-film devices

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Sandberg OJ, Nyman M, Dahlström S, Sanden S, Törngren B, Smått JH, Österbacka R
Publisher: AMER INST PHYSICS
Publication year: 2017
Journal: Applied Physics Letters
Journal acronym: APPL PHYS LETT
Volume number: 110
Issue number: 15
Number of pages: 4
ISSN: 0003-6951


Abstract

The charge extraction (of injected carriers) by linearly increasing voltage in metal-insulator-semiconductor structures, or MIS-CELIV, is based on the theory of space-charge-limited currents. In this work, the validity of MIS-CELIV for mobility determination in organic thin-film devices has been critically examined and clarified by means of drift-diffusion simulations. It is found that depending on the applied transient voltage, the mobility might be overestimated by several orders of magnitude in the case of an ohmic injecting contact. The shortcomings of the MIS-CELIV theory can be traced back to the underlying assumption of a drift-dominated transport. However, the effect of diffusion can be taken into account by introducing a correction factor. In the case of non-ohmic injecting contacts, the extracted mobility becomes strongly dependent on device parameters, possibly leading to large deviations from the actual mobility.


Keywords

Charge carrier mobility, Electric contacts, Extraction current transients, solar cells


Documents


Last updated on 2019-13-11 at 03:52