Photoresponse in large area multi-walled carbon nanotube/polymer nanocomposite films

TL;DR

This study investigates the near IR photoresponse of large-area MWNT/polymer nanocomposite films, revealing position-dependent photocurrent, enhanced response compared to pure MWNT films, and slow time constants explained by Schottky barrier modulation.

Contribution

It provides new insights into the photoresponse behavior of MWNT/polymer nanocomposites and demonstrates enhanced photoresponse compared to pure MWNT films.

Findings

Photocurrent depends on laser spot position, peaking at the metal-film interface.

Photoresponse is significantly larger in nanocomposite films than in pure MWNT films.

Photoresponse time constants range from 0.6 to 1.2 seconds, explained by Schottky barrier effects.

Abstract

We present a near IR photoresponse study of large area multi-walled carbon nanotube/poly(3-hexylthiophene)-block-polystyrene polymer (MWNT/P3HT-b-PS) nanocomposite films for different loading ratio of MWNT into the polymer matrix. We show that the photocurrent strongly depends on the position of the laser spot with maxiumum photocurrent occurring at the metal - film interface. In addition, compared to the pure MWNT film, the photoresponse is much larger in the MWNT/polymer composite films. The time constant for the photoresponse is slow and varies between 0.6 and 1.2 seconds. We explain the photoresponse by Schottky barrier modulation at the metal - film interface.