Thin Films of SiP Lamellar Alloys: A First Step toward 2D SiP

We investigate the structural and vibrational properties of Si:P thin films obtained by co-evaporation Si P in ultrahigh vacuum at room temperature followed rapid thermal annealing. The crystallization was Raman spectroscopy. Annealing temperatures larger than 950 °C leads to formation crystalline phases. Density functional theory calculations modes allow us identify orthorhombic SiP. Electron energy loss spectroscopy combined with energy-dispersive gives evidence a plasmon signature SiP phase. distribution phases film imaged energy-filtered transmission electron microscopy. Both areas having sizes few microns are found coexist films. High-resolution scanning imaging provides clear lamellar structure, while spatially resolved allows achieve chemical mapping for both atoms, which agrees quite well structure Our results represent an important first step obtain two-dimensional (2D) SiP, promising new material direct band gap has been predicted.