Injection barrier induced deviations in space charge limited conduction in doped poly(3-methylthiophene) based devices

Khan, Motiur Rahman and Varade, Vaibhav and Rao, Koteswara KSR and Menon, R (2015) Injection barrier induced deviations in space charge limited conduction in doped poly(3-methylthiophene) based devices. In: JOURNAL OF APPLIED PHYSICS, 118 (16).

PDF AIP_Jou_App_Phy_118-16_164503_2015.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

The carrier density dependent current-voltage (J V) characteristics of electrochemically prepared poly(3-methylthiophene) (P3MeT) have been investigated in Pt/P3MeT/Al devices, as a function of temperature from 280 to 84 K. In these devices, the charge transport is found to be mainly governed by different transport regimes of space charge limited conduction (SCLC). In a lightly doped device, SCLC controlled by exponentially distributed traps (Vl+1 law, l > 1) is observed in the intermediate voltage range (0.5-2 V) at all temperatures. However, at higher bias (> 2 V), the current deviates from the usual Vl+1 law where the slope is found to be less than 2 of the logJ-logV plot, which is attributed to the presence of the injection barrier. These deviations gradually disappear at higher doping level due to reduction in the injection barrier. Numerical simulations of the Vl+1 law by introducing the injection barrier show good agreement with experimental data. The results show that carrier density can tune the charge transport mechanism in Pt/P3MeT/Al devices to understand the non-Ohmic behavior. The plausible reasons for the origin of injection barrier and the transitions in the transport mechanism with carrier density are discussed. (C) 2015 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	JOURNAL OF APPLIED PHYSICS
Publisher:	AMER INST PHYSICS
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	10 Dec 2015 06:23
Last Modified:	10 Dec 2015 06:23
URI:	http://eprints.iisc.ac.in/id/eprint/52882

Actions (login required)

View Item