Impact of Defects on Electronic Properties of Heterostructures Constructed From Monolayers of Transition Metal Dichalcogenides

Abstract

Electronic properties of heterostructures composed of two single molecular layers (monolayers) of MoS2, WS2, WSe2, and MoSe2 are ab initio simulated with an emphasis to the stacking peculiarities and an influence of point defects in their lattices. MoS2/MoSe2, MoS2/WS2, WS2/WSe2, and MoSe2/WSe2 heterostructures with the monolayers shifted like in the bulk material have been found to behave like semiconductors with the energy gaps of 0.88, 1.25, 1.06, and 1.07 eV, respectively. Such heterostructures possess indirect gaps in contrast to individual monolayers, while direct‐gap character is preserved in two layer stacking variants in WS2/WSe2 heterostructures and in MoS2/MoSe2 heterostructure with mirror stacking of the monolayers. Vacancies and Te atoms substituting other chalcogen atoms reduce the band gaps. The calculated orbital compositions of first direct band gap transitions in the defect‐free heterostructures and those with the point defects have demonstrated d‐electrons of Mo or W atoms to be mainly involved in the transitions.

Electronic Properties of WS2/WSe2 Heterostructure Containing Te Impurity: The Role of Substituting Position

“…This differs from the variant, when chalcogen atom was substituted, as described in our previous paper. 5 In that case the gap was reduced as well, but the heterostructure preserved its semiconductor properties. However, the most interesting thing occurs, when Te atoms are located in both layers.…”

“…In order to investigate how Te atoms can influence on electronic properties of a two-dimensional heterostructure made of WS 2 and WSe 2 MLs, we have calculated electronic energy band structures of different variants of the Te atoms substituting metal atoms in such structures and compared with our previous results for the case when Te atoms substituted the chalcogen ones. 5 An impact of Te atomic positions was analyzed.…”

Heterostructures of two-dimensional transition metal dichalcogenides: Formation, ab initio modelling and possible applications

“…In order to determine electronic properties of such systems, an impact of the stacking arrangement as well as vacancies and substitution of atoms were analyzed for MoS2/MoSe2, MoS2/WS2, WS2/WSe2, and MoSe2/WSe2 heterostructures [29]. Several variants of two-layer heterostructures with different arrangement of layers were analyzed e.g.…”

Влияние Сжимающих И Растягивающих Напряжений На Электронную Структуру Фосфорена

“…Создание приборов нового поколения на основе слоистых материалов требует подробного исследования их свойств и условий изменения их электрофизических характеристик при различных воздействиях. Проводились исследования влияния примесей, вакансий и вариантов различного расположения слоев дихалькогенидов на их свойства [14][15][16]. Еще одной возможностью модификации свойств является деформация кристаллической решетки материала, возникающая в результате сжимающих либо растягивающих напряжений, вследствие чего у немагнитных материалов могут появляться магнитные свойства, а также меняется характер прямых и непрямых переходов [10,[17][18][19][20][21][22][23].…”