Related papers: Neutral and charged excitons interplay in non-unif…
We investigate the transport of excitons and trions in monolayer semiconductor WS$_2$ subjected to controlled non-uniform mechanical strain. We actively control and tune the strain profiles with an AFM-based setup in which the monolayer is…
Exciton mobility in two-dimensional semiconductors is a key ingredient in materials-based design of optoelectronic functionalities. Monolayer transition metal dichalcogenides (TMDs) set a good test case, with tightly bound excitons and…
Full control of excitons in 2D materials is an important step to exploit them for applications. Straintronics is one method that can be used to effectively control the movement of excitons. Unfortunately, the effects of non-uniform strain…
In two-dimensional nearly commensurate heterostructures, strain plays a critical role in shaping electronic behavior. While previous studies have focused on random strain introduced during fabrication, achieving controlled structural design…
Transition metal dichalcogenides and related layered materials in their monolayer and a few layers thicknesses regime provide a promising optoelectronic platform for exploring the excitonic- and many-body physics. Strain engineering has…
Strain engineering has quickly emerged as a viable option to modify the electronic, optical and magnetic properties of 2D materials. However, it remains challenging to arbitrarily control the strain. Here we show that by creating…
Crystalline two-dimensional (2D) semiconductors often combine high elasticity and in-plane strength, making them ideal for strain-induced tuning of electronic characteristics, akin to strategies used in silicon electronics. However,…
Mechanical strain is a powerful tuning knob for excitons, Coulomb-bound electron-hole complexes dominating optical properties of two-dimensional semiconductors. While the strain response of bright free excitons is broadly understood, the…
Unconventional emissions from exciton and trion in monolayer WS2 are studied by photoexcitation. Excited by 532nm laser beam, the carrier species in the monolayer WS2 are affected by the excess electrons escaping from photoionization of…
Over the past few decades, thin film optoelectronic devices based on transition metal dichalcogenides (TMDs) have made significant progress. However, the sensitivity of the exciton states to environmental change presents challenges for…
Controlling resonant Raman scattering in two-dimensional semiconductors typically requires tuning the excitation energy to match excitonic transitions. Here we show that mechanical deformation can achieve the same effect without changing…
Strain is a powerful tool to modify the optical properties of semiconducting transition metal dichalcogenides like MoS2, MoSe2, WS2 and WSe2. In this work we provide a thorough description of the technical details to perform uniaxial strain…
A method is presented for optically preparing WS2 monolayers to luminesce from only the charged exciton (trion) state--completely suppressing the neutral exciton. When isolating the trion state, we observed changes in the Raman A1g…
We perform micro-photoluminescence and Raman experiments to examine the impact of biaxial tensile strain on the optical properties of WS2 monolayers. A strong shift on the order of -130 meV per % of strain is observed in the neutral exciton…
Nonlinear optical frequency conversion, in which optical fields interact with a nonlinear medium to produce new field frequencies, is ubiquitous in modern photonic systems. However, the nonlinear electric susceptibilities that give rise to…
Strain engineering, which aims to tune the bandgap of a semiconductor by the application of strain, has emerged as an interesting way to control the electrical and optical properties of two-dimensional (2D) materials. Apart from the changes…
Layered two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have recently attracted remarkable attention because of their unique physical properties. Here, we use photoluminescence (PL) and Raman spectroscopy to study…
The ultrathin transition metal dichalcogenides (TMDs) have emerged as promising materials for various applications using two dimensional (2D) semiconductors. They have attracted increasing attention due to their unique optical properties…
Strain engineering can modulate the material properties of two-dimensional (2D) semiconductors for electronic and optoelectronic applications. Recent theory and experiments have found that uniaxial tensile strain can improve the electron…
The tunability of the bandgap, absorption and emission energies, photoluminescence (PL) quantum yield, exciton transport, and energy transfer in transition metal dichalcogenide (TMD) monolayers provides a new class of functions for a wide…