In the last decade, more and more 2D crystals have been uncovered and synthesized. Single-atomic-layer graphene was peeled off by adhesive tape from graphite in 2004 since then, graphene-like 2D materials have been gradually brought into the limelight. More importantly, the strain tuning electric and optoelectric in low-dimensional semiconductors give rise to many high-performance and multifunctional fascinating devices which will be applied widely in semiconductor technology. Meanwhile, the properties of nanomaterials are sensitive to the strain due to the ultrathin size which can be used to manufacture sensors and offers method to improve their properties. Interestingly, the mechanical properties of materials become more excellent when their size decreases to the nanoscale, which facilitate their application on the fabrication of flexible devices. For bulk materials, the piezoelectric effect always exists in brittle materials, such as piezoelectric ceramics, and the piezoresistive effect has been well studied in semiconductors. The strain-induced piezoelectric and piezoresistive effects are two crucial mechanisms in wurtzite-structured and asymmetric structure crystal. The introduction of strain into semiconductors is significant to the studies involving basic science as well as device applications. Strain engineering has become a strong approach to improve the performance of functional materials, especially for semiconductors. At last, we in-depth discussed future research directions of strain-engineered 2D semiconductor and related electronics and optoelectronics device applications. Furthermore, the applications of strain-engineered 2D semiconductors in sensors, photodetectors and nanogenerators are also highlighted. Moreover, recent advances in experimental observation of strain tuning PL spectra and transport behavior of 2D semiconductors are summarized. In this review, starting with the fundamental theories of piezoelectric and piezoresistive effect resulted by strain, following we reviewed the recent simulation works of strain engineering in novel 2D semiconductors, such as Janus 2D and 2D-Xene structures. The strain-engineered one-dimensional materials have been well investigated, while there is a long way to go for 2D semiconductors. The excellent flexibility and outstanding mechanical strength of 2D semiconductors provide opportunities for fabricated strain-sensitive devices and utilized strain tuning their electronic and optic–electric performance. The development of two-dimensional (2D) semiconductors has attracted widespread attentions in the scientific community and industry due to their ultra-thin thickness, unique structure, excellent optoelectronic properties and novel physics.
0 Comments
Leave a Reply. |