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

Abstract

Due to miniaturization of device dimensions, the next generation’s 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–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.

High performing flexible optoelectronic devices using thin films of topological insulator

“…2 and 3 and the fitted curves can be found in the Figure S2 . The increase in laser power shows the increase in the photocurrent and such effect was also studied earlier 47 . The photocurrent also depends on the applied voltage because the transit time ( ) of the carriers through the device channel is given by where l = channel length and = carrier mobility.…”

Graphene actively Q-switched lasers

“…(b) Photoresponsivity comparison of this work and typical previous results (i.e. WSe2/BP/MoS2 [210], Bi2Te3, [207] WS2/Bi2Te3, [209] Graphene, [208] BP, [212,213,232,235] SnTe/Si, [211] MoTe2/MoS2, [198] BP/WSe2, [236] Graphene/Bi2Te3, [237] MoS2/PbS, [238] MoS2/BP, [239] and MoS2/Graphene/WSe2 [86]) at = 1550 nm. Publication I.…”

Device Applications of Synthetic Topological Insulator Nanostructures

“…It is worth to mention that the FIB fabrication of nanowires involves harsh exposure environment with An alternative approach to enhance the surface contribution of the photocurrent is to use non-planar synthetic topological insulator nanostructures with larger surface-to-volume ratio such as nanowires and nanoribbons. For example, very recently in 2017, broad spectral photodetection from ultra-violet to near-infra-red was reported based on a Bi 2 Te 3 nanowire photodetector [50]. Device performance was compared between the exfoliated Bi 2 Te 3 nanosheets and the Bi 2 Te 3 nanowires which were fabricated by milling the nanosheet using focused ion beam (FIB).…”