High performing flexible optoelectronic devices using thin films of topological insulator

Abstract

Topological insulators (TIs) possess exciting nonlinear optical properties due to presence of metallic surface states with the Dirac fermions and are predicted as a promising material for broadspectral phodotection ranging from UV (ultraviolet) to deep IR (infrared) or terahertz range. The recent experimental reports demonstrating nonlinear optical properties are mostly carried out on non-flexible substrates and there is a huge demand for the fabrication of high performing flexible optoelectronic devices using new exotic materials due to their potential applications in wearable devices, communications, sensors, imaging etc. Here first time we integrate the thin films of TIs (Bi2Te3) with the flexible PET (polyethylene terephthalate) substrate and report the strong light absorption properties in these devices. Owing to small band gap material, evolving bulk and gapless surface state conduction, we observe high responsivity and detectivity at NIR (near infrared) wavelengths (39 A/W, 6.1 × 108 Jones for 1064 nm and 58 A/W, 6.1 × 108 Jones for 1550 nm). TIs based flexible devices show that photocurrent is linearly dependent on the incident laser power and applied bias voltage. Devices also show very fast response and decay times. Thus we believe that the superior optoelectronic properties reported here pave the way for making TIs based flexible optoelectronic devices.

Stabilization of Orthorhombic CoSe2 by 2D-rGO/MWCNT Heterostructures for Efficient Hydrogen Evolution Reaction and Flexible Energy Storage Device Applications

“…) − have become the top contenders. In particular, metal selenides have been previously studied for OER, HER, dye-sensitized solar cells, batteries, optoelectronic devices, and so forth, predominantly owing to their structural diversity, multivalent oxidation states, earth abundance, and tunable physicochemical properties. Cobalt based materials are commendable for catalytic HER and energy storage owing to their abundance and catalytic activity compared to Fe and Ni.…”

Ultrasensitive and Self‐Powered SnSe/Ge Heterojunction Photodetector Driven by Spontaneously Interfacial Excitation Transfer of Carriers

“…[14][15][16][17][18] Consequently, benefiting from the existence of Dirac surface state on TCI phase SnSe crystal, it is advantageous to realize the predominated transport of surface carriers with no backscattering and higher mobility. [19][20][21][22] Whereas, for the SnSe crystal with orthorhombic lattice structure, it is favorable for the layer-by-layer growth pattern. This can help to create SnSerelated heterojunctions with sharp interfaces.…”

Fabrication of Topological Insulator Bi2Se3−PbSe Heterojunction Photodetector for Infrared Detection

“…With the capability to function under zero bias, the as‐fabricated Bi 2 Se 3 −PbSe heterojunction photodetector can exhibit a very low dark noise level, which is beneficial for achieving superior detectivity in comparison with the Bi 2 Se 3 ‐based photoconductors. [ 28,29 ] Rising and falling time in a single on/off cycle is shown in Figure 3b. With a sampling interval of 5 ms, the rising time and falling time are both shorter than 5 ms. Due to the fast charge transport capability of Bi 2 Se 3 , an elevated response speed is obtained in the as‐fabricated Bi 2 Se 3 −PbSe heterojunction photodetector compared with the PbSe‐based photoconductors, whose response time is up to several seconds.…”

“…With a sampling interval of 5 ms, the rising time and falling time are both shorter than 5 ms. Due to the fast charge transport capability of Bi 2 Se 3 , an elevated response speed is obtained in the as‐fabricated Bi 2 Se 3 −PbSe heterojunction photodetector compared with the PbSe‐based photoconductors, whose response time is up to several seconds. [ 29,30 ] Thus, high photosensitivity as well as rapid response are concurrently realized in the Bi 2 Se 3 −PbSe heterojunction photodetector.…”