A new binary phase in the tin monoselenide system: chemical epitaxy of orthorhombic γ-SnSe thin films

Abstract

A new orthorhombic binary phase in the tin mono-selenide system, γ-SnSe, was deposited from solution onto an intermediate layer of PbS on GaAs substrates. Its structure is based on orthorhombic lead telluride (PbTe) which was reported to exist at high pressures, yet has never been observed in SnSe. The proposed model of γ-SnSe was experimentally determined using X-ray diffraction with lattice parameters a₀ = 0.8332 nm, b₀ = 0.4136 nm, c₀ = 0.6115 nm, R_p = 5.96, and R_wp = 8.16. The films show heteroepitaxial relations with the underlying layer of PbS.