In situ x-ray scattering investigation of PtSe ₂ grown via thermally assisted conversion

Abstract Platinum diselenide (PtSe 2 ) is a promising material for next-generation optoelectronic and electronic devices. Scalable production of high-quality PtSe 2 is therefore highly desirable. Consequently, thin-film growth techniques such as chemical vapor deposition and thermally assisted conversion (TAC) have gained increasing attention. In this study, we employed real-time, in-situ grazing-incidence wide-angle x-ray scattering to characterize the PtSe 2 growth process via TAC of pre-deposited Pt layers. We directly monitored the phase formation of PtSe 2 through its prominent 001 diffraction peak. Tracking the crystallization of few-layer PtSe 2 layers in real-time allowed us to estimate the activation energy using the Avrami crystallization model. We also identified a minimum temperature for obtaining the crystalline phase. Growth of horizontally aligned PtSe 2 was observed without the presence of any metastable transition phase throughout the selenization process. Higher growth temperatures drive anisotropic lattice evolution in PtSe 2 , resulting in reduced thickness and reduced lattice mismatch through lattice rotation.