Bandgap engineering of strained monolayer semiconductor δ-Cu2S and its outstanding mechanical flexibility

Radiocesium Contamination on a University Campus and in Forests in Kashiwa City, Chiba Prefecture, a Suburb of Metropolitan Tokyo

“…5. The η-Au 2 S has a direct band gap of 1.02 eV at γ point, whereas the band gap is closed for the θ-Au 2 S. This kind of band gap modulation in the electronic bands of ηand θ-Cu 2 S by using uniaxial and biaxial stress has been reported previously [8,10,11,30].…”

“…1 (a), is comprehended as a distorted structure of Au 2 S [P 42 1 2(90)]. The geometrical structure of Au 2 S [P 42 1 2(90)] and Au 2 S [P 4/nmm(129)] have already reported in the study about Cu 2 S [10,11]. However, Au 2 S [P 42 1 2(90)] and Au 2 S [P 4/nmm(129)] are not the most stable structure, researchers have not given a detailed analysis of the electronic structure of them.…”

Electronic band structure change with structural transition of buckled Au2X monolayers induced by strain

“…The Z-Au 2 S has a direct band gap of 1.02 eV at G point, whereas the band gap is closed for the y-Au 2 S. This kind of band gap modulation in the electronic bands of Zand y-Cu 2 S by using uniaxial and biaxial stress has been reported previously. 8,10,11,30 S2 and S3 in ESI. † Here, we denote the contribution from s type functions of Au atoms as Au-s. We also denote the valence (conduction) bands as VB1 (CB1), VB2 (CB2), and so on, in order of proximity to the Fermi level.…”

“…The η -Au 2 S has a direct band gap of 1.02 eV at Γ point, whereas the band gap is closed for the θ -Au 2 S. This kind of band gap modulation in the electronic bands of η - and θ -Cu 2 S by using uniaxial and biaxial stress has been reported previously. 8,10,11,30 In ref. 11, based on the partial DOS analysis, the researchers have revealed that the valence band maximum (VBM) of θ -Cu 2 S is dominantly contributed by the hybridization of p x , p y atomic orbitals of S atoms and d xy atomic orbitals of Cu atoms, whereas the conduction band minimum (CBM) of θ -Cu 2 S is mainly from the p x , p y atomic orbitals of Cu atoms.…”

“…1(a), is comprehended as a distorted structure of Au 2 S [ P 42 1 2 (90)]. The geometrical structure of Au 2 S [ P 42 1 2 (90)] and Au 2 S [ P 4/ nmm (129)] have already been reported in the study about Cu 2 S. 10,11 However, since Au 2 S [ P 42 1 2 (90)] and Au 2 S [ P 4/ nmm (129)] are not the most stable structure, researchers have not given a detailed analysis of the electronic structure of them. Although the most stable structure discussed in ref.…”