Wang Tianxing

Electronic properties of the SnSe–metal contacts: First-principles study*

The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calculation. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on M (M = Ag, Au, Ta) substrate. Compared with the corresponding free-standing monolayer SnSe, the adsorbed SnSe undergoes a semiconductor-to-metal transition. The potential difference ΔV indicates that SnSe/Ta contact is the best candidate for the Schottky contact of the three SnSe/M contacts. Two types of current-in-plane (CIP) structure, where a freestanding monolayer SnSe is connected to SnSe/M, are identified as the n-type CIP structure in SnSe/Ag contact and p-type CIP structure in SnSe/Au and SnSe/Ta contact. The results can stimulate further investigation for the multifunctional SnSe/metal contact.

Theoretical investigation of the elastic, electronic, thermodynamic and optical properties of the zinc-blende structure AlN under high pressure

The elastic, electronic, thermodynamic and optical properties of the zinc-blende structure aluminum nitride (AlN) under high pressure have been investigated using first-principles calculations. The dependencies of the elastic constants, the bulk modulus, the shear modulus and energy gaps on the applied pressure are presented, and the results are in good agreement with comparable experimental and theoretical values. Also, the energy band structure and density of states under high pressure have been analysed. Furthermore, the optical constants, including the dielectric function, optical reflectivity, refractive index and electron energy loss, are discussed for radiation up to 50 eV.