Effects of Diffusion on Photocurrent Generation in Single-Walled Carbon Nanotube Films

TL;DR

This study investigates how charge carrier diffusion influences photocurrent generation in single-walled carbon nanotube films, revealing that electrode spacing and illumination position significantly affect the photocurrent response.

Contribution

It demonstrates that photocurrent response in CNT films is governed by charge diffusion, with electrode spacing and illumination position playing critical roles.

Findings

Photocurrent depends strongly on illumination position, peaking at electrode edges.

Response decay follows an exponential trend related to electrode spacing.

Faster responses are observed in samples with smaller electrode spacing.

Abstract

We have studied photocurrent generation in large carbon nanotube (CNT) films using electrodes with different spacings. We observe that the photocurrent depends strongly on the position of illumination, with maximum observed response occurring upon illumination at the electrode edges. The rate of change of the response decays exponentially, with the fastest response occurring for samples with the smallest electrode spacing. We show that the time response is due to charge carrier diffusion in low-mobility CNT films.