Robust broad spectral photodetection (UV-NIR) and ultra high responsivity investigated in nanosheets and nanowires of Bi2Te3 under harsh nano-milling conditions

TL;DR

This study demonstrates that Bi2Te3 nanosheets and nanowires exhibit broad spectral photodetection from UV to NIR with ultra-high responsivity, maintaining stability under harsh fabrication conditions, advancing robust nanodevices for optoelectronics.

Contribution

It introduces a novel fabrication process for Bi2Te3 nanostructures with enhanced photodetection performance across a broad spectrum under harsh conditions.

Findings

Bi2Te3 nanosheets achieve ~74 A/W responsivity at 1550 nm

Nanowires show an order of magnitude increase in responsivity

Devices remain stable after 4 months in ambient conditions

Abstract

Due to miniaturization of device dimensions, the next generations photodetector based devices are expected to be fabricated from robust nanostructured materials. Hence there is an utmost requirement of investigating exotic optoelectronic properties of nanodevices fabricated from new novel materials and testing their performances at harsh conditions. The recent advances on 2D layered materials indicate exciting progress on broad spectral photodetection (BSP) but still there is a great demand for fabricating ultra-high performance photodetectors made from single material sensing broad electromagnetic spectrum since the detection range 325 nm to 1550 nm is not covered by the conventional Si or InGaAs photodetectors. Alternatively, Bi2Te3 is a layered material, possesses exciting optoelectronic, thermoelectric, plasmonics properties. Here we report robust photoconductivity measurements on Bi2Te3 nanosheets and nanowires demonstrating BSP from UV to NIR. The nanosheets of Bi2Te3 show the best ultra-high photoresponsivity (~74 A/W at 1550 nm ). Further these nanosheets when transform into nanowires using harsh FIB milling conditions exhibit about one order enhancement in the photoresponsivity without affecting the performance of the device even after 4 months of storage at ambient conditions. An ultra-high photoresponsivity and BSP indicate exciting robust nature of topological insulator based nanodevices for optoelectronic applications.