Ferroelectric semiconductor α-In₂Se₃ has gained significant attention due to its favorable physical characteristics, including an appropriate bandgap (≈1.4 eV) for semiconductor devices, intercorrelated out-of-plane and in-plane polarization, and high Curie temperature (>200 °C). Combining its semiconducting and ferroelectric properties, α-In₂Se₃ holds promise for developing many innovative applications. However, the large-scale synthesis of uniform layered α-In₂Se₃ for practical use and a comprehensive understanding of its phase transition during synthesis are lacking. In this study, layered α-In₂Se₃ on amorphous SiO₂ substrates at a cm²-scale is successfully synthesized and explored its phase transition during synthesis, by using a 2D solid-phase crystallization (2DSPC) method with a SiO₂ encapsulation. The formation of highly crystalline 2D layered α-In₂Se₃ is observed through the real-time β-phase to α-phase transition at room temperature. The electrical (field-effect mobility µ_FE ≈ 1 cm² V⁻¹s⁻¹), optical, and ferroelectric properties of the synthesized α-In₂Se₃ thin films are further investigated. This study contributes to the understanding and control of stoichiometry and phases of In₂Se₃ and provides an efficient approach for synthesizing large-area 2D layered α-In₂Se₃.

中文翻译：

---

二维固相结晶法合成大面积层状铁电半导体α-In2Se3及其相变


铁电半导体α-In ₂ Se ₃ 因其良好的物理特性而受到广泛关注，包括适合半导体器件的合适带隙（≈1.4 eV）、互相关面外和面内偏振，以及高居里温度（>200°C）。 α-In ₂ Se ₃ 结合了其半导体和铁电特性，有望开发许多创新应用。然而，用于实际应用的均匀层状α-In ₂ Se ₃ 的大规模合成以及对其合成过程中相变的全面了解还缺乏。本研究成功合成了 cm ² 尺度的非晶 SiO ₂ 衬底上的层状 α-In ₂ Se ₃ ，并通过使用 SiO ₂ 封装的二维固相结晶 (2DSPC) 方法，探索了其合成过程中的相变。通过室温下实时 β 相到 α 相的转变，观察到高度结晶的二维层状 α-In ₂ Se ₃ 的形成。电学（场效应迁移率 µ _FE ≈ 1 cm ² V ⁻¹ s ⁻¹ ）、光学和铁电特性进一步研究了合成的α-In ₂ Se ₃ 薄膜。该研究有助于理解和控制In ₂ Se ₃ 的化学计量和物相，并为合成大面积二维层状α-In ₂ 。