On Wannier exciton 2D localization in hydrogen intercalated InSe and GaSe layered semiconductor crystals

• Published in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Date: 2004
• Main Authors: Zhirko, Yu.I., Zharkov, I.P., Kovalyuk, Z.D., Pyrlja, M.M., Boledzyuk, V.B.
• Format: Article
• Language: English
• Published: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2004
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/119208
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: On Wannier exciton 2D localization in hydrogen intercalated InSe and GaSe layered semiconductor crystals / Yu.I. Zhirko, I.P. Zharkov, Z.D. Kovalyuk, M.M. Pyrlja, V.B. Boledzyuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2004. — Т. 7, № 4. — С. 404-410. — Бібліогр.: 22 назв. — англ.

Exciton absorption spectra of layered InSe and GaSe crystals electrochemically intercalated by hydrogen were investigated. It was found that the observed at T = 80 K non-monotonic shift of the exciton absorption peak n = 1 with growing hydrogen concentration x (here x is the amount of hydrogen atoms per a formula unit of a crystal matrix) stems from the increasing dielectric permittivity of the crystal ε₀ due to availability of hydrogen in the van der Waals gap. Growth of ε₀(x) results in decrease of the exciton binding energy but, at larger x concentrations (when the anisotropy parameter ε*(х) grows), 2D localization of exciton motion in the crystal layer plane takes place, which causes reduction and then, at x > 1, stabilization of sizes both for the exciton and quantum well.