Nanotechnology for photosensitive structure metall-dielectric (oxide)-semiconductor

NANOTECHNOLOGY FOR PHOTOSENSITIVE

STRUCTURE METALL-DIELECTRIC (OXIDE)-SEMICONDUCTOR

D.Melebayev

Sun Energy Institute of Academy of Science of Turkmenistan

dmelebay@yandex.ru

Photosensitive MIS nanostructures Au-Ga₂O₃(Fe)-n-GaP were made by chemical deposition method. Photoelectric and electric properties of this structures were researched. The oxide layer Ga₂O₃(Fe) morphology and structure were investigated on transmission and atomic-force electron microscopes. New regularity were discovered in visible (2-3 eV) and ultraviolet (UV) (5-6.2 eV) spectral regions. A spectral maximum was observed in long-wave spectral region (hν_m = 2.35 eV). This accounts for iron nanooxide formation on the interface semiconductor-dielectric with energy gap width E_g≈ 2.2 eV (300 K). In UV region at hν > 5.1 eV huge photosensitivity was discovered, this accounts for avalanche multiplication in a space-charge layer and properties of nanolayers of the metal Au and of the high energy-gap oxide Ga₂O₃(Fe). In a oxide layer nanowires with iron oxide were discovered, 25-45 nm in diameter and it's length was 10-12 μm. Typical value of structure current photosensitivity nearly hν = 6.0 eV achieves ~0.25 A/W under zero voltage bias. There's demonstrate that short-wave UV radiation is strongly absorbed in nanowires. This effects in photosensitive MIS nanostructures give an opportunity the new types of UV radiation photodetectors for practical application.

Keywords: huge photosensitivity, MIS nanostructure, ultraviolet photodetectors, gallium oxide, ferric oxide.