AUTHOR=Chuai Ya-Hui , Zhu Chao , Yue Dan , Bai Yu TITLE=Epitaxial Growth of Bi2Se3 Infrared Transparent Conductive Film and Heterojunction Diode by Molecular Beam Epitaxy JOURNAL=Frontiers in Chemistry VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.847972 DOI=10.3389/fchem.2022.847972 ISSN=2296-2646 ABSTRACT=

Epitaxial n-type infrared transparent conductive Bi₂Se₃ thin film was cultivated by molecular beam epitaxy (MBE) method on Al₂O₃ (001) substrate. The orientation between Bi₂Se₃ and the substrate is Bi₂Se₃(001)//Al₂O₃(1 2¯ 10). Conducting mechanism ensued the small-polaron hopping mechanism, with an activation energy of 34 meV. The film demonstrates conductivity of n-type, and the resistivity is 7 × 10⁻⁴ Ωcm at room temperature. The Film exhibits an excellent carrier mobility of 1,015 cm²/Vs at room temperature and retains optical transparency in the near-infrared (>70%) and far-infrared (>85%) ranges. To the best of our knowledge, the Bi₂Se₃ film yields the best result in the realm of n-type Infrared transparent conductive thin films generated through either physical or chemical methods. To demonstrate the application of such films, we produced N-Bi₂Se₃/P-CuScO₂ heterojunction diode device, the ∼3.3 V threshold voltage of which conformed fairly well with the CuScO₂ bandgap value. The high optical transparency and conductivity of Bi₂Se₃ film make it very promising for optoelectronic applications, where a wide wavelength range from near-infrared to far-infrared is required.