Evidence of the direct-to-indirect band gap transition in strained two-dimensional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>WS</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>MoS</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math>, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>WSe</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math>
Elena Blundo, Marco Felici, Tanju Yildirim, Giorgio Pettinari, Davide Tedeschi, A. Miriametro, B. Liu, Wendi Ma, Yuerui Lu, A. Polimeni
Abstract
This paper reports the effects of high strains on the optoelectronic properties of 2D crystals. By realizing micro- and nano-domes made of single layer transition-metal dichalcogenides, the authors demonstrate the possibility to induce a clear-cut crossover from direct to indirect bandgap in strained monolayers. The indirect excitons can be harvested and potentially stored for long times, which is relevant for flexible photovoltaics devices and for inducing bosonic condensation.
Topics & Concepts
PhotovoltaicsMonolayerExcitonBand gapMaterials scienceCondensed matter physicsOptoelectronicsPhysicsNanotechnologyPhotovoltaic systemElectrical engineeringEngineering2D Materials and ApplicationsGraphene research and applicationsMXene and MAX Phase Materials