Strain‐Engineered Anisotropic Optical and Electrical Properties in 2D Chiral‐Chain Tellurium

Abstract

Atomically thin materials, leveraging their low‐dimensional geometries and superior mechanical properties, are amenable to exquisite strain manipulation with a broad tunability inaccessible to bulk or thin‐film materials. Such capability offers unexplored possibilities for probing intriguing physics and materials science in the 2D limit as well as enabling unprecedented device applications. Here, the strain‐engineered anisotropic optical and electrical properties in solution‐grown, sub‐millimeter‐size 2D Te are systematically investigated through designing and introducing a controlled buckled geometry in its intriguing chiral‐chain lattice. The observed Raman spectra reveal anisotropic lattice vibrations under the corresponding straining conditions. The feasibility of using buckled 2D Te for ultrastretchable strain sensors with a high gauge factor (≈380) is further explored. 2D Te is an emerging material boasting attractive characteristics for electronics, sensors, quantum devices, and optoelectronics. The results suggest the potential of 2D Te as a promising candidate for designing and implementing flexible and stretchable devices with strain‐engineered functionalities.

Review of Anisotropic 2D Materials: Controlled Growth, Optical Anisotropy Modulation, and Photonic Applications

“…[14] The similar crystalline structure in black arsenic (B-As) also renders its superior in-plane anisotropy than other known 2D crystals. [15] Apart from the puckered BP or B-As, other elemental semiconductors with distorted hexagonal structures, such as antimonene, [16,93] tellurium, [17] fibrous red phosphorene, [18] and borophene, [19] show strong in-plane optical or electrical anisotropies as well.…”

A high performance self-powered photodetector based on a 1D Te–2D WS2 mixed-dimensional heterostructure

“…The heterostructures based phototransistors displayed obvious anti-ambipolar transport and rectification behavior as well as a high photoresponsivity of 10 3 A/W and a fast response time of 15 ms under 1550 nm communication wavelength [29]. Above all, a number of research groups have focused on the spintronic, electronic and photo-response properties of Te nanosheet and nanowire [30][31][32][33][34][35][36][37][38], while the photodetection properties of Te microwire based mixeddimensional heterostructure is rarely reported. Noticeably, the large dark current and ultrafast electron-hole recombination rate of Te are the main disadvantages for further application because of the narrow band gap of Te in bulk.…”

Study of the Growth Mechanism of Solution‐Synthesized Symmetric Tellurium Nanoflakes at Atomic Resolution

“…Nanodevices based on 2D Te have been reported to achieve outstanding performance. [ 18,25–29 ] For example, 2D Te field‐effect transistors exhibit huge on/off ratios (≈10 6 ) and high field‐effect mobilities (≈700 cm 2 V −1 s −1 ). [ 18 ] Te nanoflake‐based short‐wave infrared photodetectors with optical cavity substrates composed of Au/Al 2 O 3 possess high photoresponsivity.…”