Interlayer and intralayer excitons in AlN/WS$_2$ heterostructure

Claudio Attaccalite (1) , M. S. Prete , M. Palummo (2, 3) , O. Pulci (2, 3)

1 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
2 Department of Physics [Roma Tor Vergata]
3 INFN - Istituto Nazionale di Fisica Nucleare

Transition metal dichalcogenides (TMD) monolayers, holding potential as good sunlight absorbers, are promising materials for next-generation optoelectronic devices. They may enable ultrathin photovoltaic(PV) devices thanks to their semiconducting character. In addition, heterocombinations of AlN and GaN sheets with MoS$_2$ monolayers have been suggested to be efficient water-splitting devices. Following these promising findings and motivated by the small lattice mismatch, we take up the idea of coupling a semiconducting WS$_2$ TMD monolayer with a AlN monolayer in a vdW heterostructure which is, as well, promising for photo-catalysis or photo-voltaic devices. We study this heterostructure by means of first principles calculations, and we show that many-body effects change the heterostructure band alignment from type II to I, demonstrating how their inclusion is compulsory for a correct prediction of the electronic and optical properties of 2D materials.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Claudio Attaccalite, M. S. Prete, M. Palummo, O. Pulci. Interlayer and intralayer excitons in AlN/WS$_2$ heterostructure. Materials, 2022, 15 (23), pp.8318. ⟨10.3390/ma15238318⟩. ⟨hal-03717052⟩