Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures

Kuiri, Manabendra and Chakraborty, Biswanath and Paul, Arup and Das, Subhadip and Sood, AK and Das, Anindya (2016) Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures. In: APPLIED PHYSICS LETTERS, 108 (6).

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Abstract

MoTe2 with a narrow band-gap of similar to 1.1 eV is a promising candidate for optoelectronic applications, especially for the near-infrared photo detection. However, the photo responsivity of few layers MoTe2 is very small (<1mAW(-1)). In this work, we show that a few layer MoTe2-graphene vertical heterostructures have a much larger photo responsivity of similar to 20mAW(-1). The trans-conductance measurements with back gate voltage show on-off ratio of the vertical transistor to be similar to(0.5-1) x 10(5). The rectification nature of the source-drain current with the back gate voltage reveals the presence of a stronger Schottky barrier at the MoTe2-metal contact as compared to the MoTe2-graphene interface. In order to quantify the barrier height, it is essential to measure the work function of a few layers MoTe2, not known so far. We demonstrate a method to determine the work function by measuring the photo-response of the vertical transistor as a function of the Schottky barrier height at the MoTe2-graphene interface tuned by electrolytic top gating. (C) 2016 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	APPLIED PHYSICS LETTERS
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:	29 Apr 2016 05:51
Last Modified:	29 Apr 2016 05:51
URI:	http://eprints.iisc.ac.in/id/eprint/53737

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