  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.
