We report on a new layered semiconductor Tl 8 Sn 10 Sb 16 Se 48 with an indirect band gap of 0.45 eV. The novel structure is made of alternating layers of SnSe 2 -type [Sn 5 Sb 2 Se 14 ] and SnSe-type [Tl 4 Sb 6 Se 10 ]. The material exhibits two-dimensional (2D) electron variable range hopping at low temperatures, indicating an absence of interlayer coherency of the electronic state. Theoretical calculations unveil a 2D confinement for electrons in the [Sn 5 Sb 2 Se 14 ] sheet and confirm the heterostructure nature. This unique electronic structure is attributed to the weak interlayer coupling and structure distortion in the electron-poor [Tl 4 Sb 6 Se 10 ] layer that energetically impedes electron propagation.
ASJC Scopus subject areas
- Colloid and Surface Chemistry