Si(111)邻位面衬底上InSb薄膜的外延生长及其可见光电导特性

Heteroepitaxial Growth of InSb Thin Films on Si(111) Vicinal Substrates and Their Visible Light Photoconductive Properties

摘要:

锑化铟(InSb)因其在红外探测、高速电子学和量子计算等领域的卓越性能备受关注。文章探索了Si(111)邻位面衬底上InSb薄膜的异质外延生长,并研究了其光电导特性。尝试采用Bi缓冲层结合InSb两步法生长策略解决Si与InSb晶格失配和热膨胀系数差异大的问题,在平坦Si(111)衬底上获得了高质量InSb(111)单晶薄膜。然而,在具有高密度台阶结构特征的Si(111)斜切衬底表面上生长得到的Bi(001)缓冲层存在大量倒反畴缺陷,在该表面上进一步生长得到的InSb薄膜均为多晶结构。所制备的InSb/Bi/Si异质结构在模拟日光辐照条件下显示出负光电导效应,应与异质结构界面态对InSb层光生载流子的捕获效应有关。

Abstract:

Indium antimonide (InSb) has attracted significant attention owing to its exceptional performance in various fields, including infrared detection, high-speed electronics, and quantum computing. This study explores the heteroepitaxial growth of InSb thin films on Si(111) vicinal substrates and investigates their visible light photoconductive properties. To address the lattice mismatch and thermal expansion coefficient discrepancy between Si and InSb, a Bi buffer layer was employed in conjunction with a two-step growth strategy, enabling the successful fabrication of high-quality single-crystalline InSb(111) thin films on Si(111) planar substrates. However, on Si(111) vicinal substrates exhibiting a high-density step structure, the grown Bi(001) buffer layers exhibited numerous anti-phase domain defects, leading to the formation of polycrystalline InSb thin films on these surfaces. The fabricated InSb/Bi/Si heterostructures displayed a negative photoconductivity effect under simulated solar illumination, which is attributed to the trapping of photogenerated charge carriers in the interfacial states of the heterostructure.