Planar carbon nanotube-graphene hybrid films for high-performance broadband photodetectors

TL;DR

This paper presents a hybrid carbon nanotube-graphene film that enables broadband photodetectors with high responsivity and fast response times, advancing scalable all-carbon optoelectronic device fabrication.

Contribution

The study introduces a novel hybrid nanostructure achieving high photoconductive gain and broadband detection, surpassing previous limitations in graphene-based photodetectors.

Findings

Photoconductive gain of ~10^5 electrons per photon

Broadband detection from 400 nm to 1550 nm

High responsivity (>100 AW^{-1}) and fast response (~100 μs)

Abstract

Graphene has emerged as a promising material for photonic applications fuelled by its superior electronic and optical properties. However, the photoresponsivity is limited by the low absorption cross section and ultrafast recombination rates of photoexcited carriers. Here we demonstrate a photoconductive gain of $\sim$ 10$^5$ electrons per photon in a carbon nanotube-graphene one dimensional-two dimensional hybrid due to efficient photocarriers generation and transport within the nanostructure. A broadband photodetector (covering 400 nm to 1550 nm) based on such hybrid films is fabricated with a high photoresponsivity of more than 100 AW$^{-1}$ and a fast response time of approximately 100 {\mu}s. The combination of ultra-broad bandwidth, high responsivities and fast operating speeds affords new opportunities for facile and scalable fabrication of all-carbon optoelectronic devices.