Molten Salt‐Assisted Synthesis of SnSe _x Thin Films With Tailored Phases and Orientations

ABSTRACT

Precise control over the phase constitution and crystallographic orientation of thin films is vital for high‐performance electronics. Herein, a salt‐assisted atmospheric pressure chemical vapor deposition (SA‐APCVD) strategy is reported for the Sn–Se system. By employing a dual‐heating‐zone configuration and optimizing source‐to‐substrate distances, the Sn/Se molar flux at the growth front was continuously modulated. The substrate temperature ( T _s ) plays a critical role in governing the phase evolution of the as‐deposited films. At T _s ≤ 742 K, the films crystallize into a hexagonal SnSe ₂ phase with Lotgering factor ( F ₀₀₁ = 0.99), whereas a transition to (400)‐oriented orthorhombic SnSe occurs above 806 K. Furthermore, the (001) texture of SnSe ₂ can be effectively tailored by adjusting the precursor molar ratio, yielding a substantial ΔF ₀₀₁ of up to 0.29. This strategy facilitates deterministic modulation of carrier types and transport characteristics, providing a robust framework for the programmable synthesis of SnSe _x films with tailored phases and textures.