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

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


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Publikationens författare: Sandberg OJ, Nyman M, Dahlström S, Sanden S, Törngren B, Smått JH, Österbacka R
Förläggare: AMER INST PHYSICS
Publiceringsår: 2017
Tidskrift: Applied Physics Letters
Tidskriftsakronym: APPL PHYS LETT
Volym: 110
Nummer: 15
Antal sidor: 4
ISSN: 0003-6951


Abstrakt

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.


Nyckelord

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


Dokument


Senast uppdaterad 2019-07-12 vid 03:37