Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Thin

Preparation and Study of Electrical Characteristics of (n-CdS/p-Ge) Thin-Film Heterojunction

Ahmed Shukur Hameed

Engineering and Technology Journal, 2009, Volume 27, Issue 9, Pages 1701-1710

A thin film (400±5 nm) of Germanium was deposited on the slide glass, then
another thin film (200±3 nm) of Cadmium Sulphide directly deposited on the Ge thin
film, with high purity (99.999%) Aluminum metal was used as O’hmic contact on two
sides of heterojunction (n-CdS/p-Ge) by vacuum thermal evaporation technique.
From ideality factor (n) values, the current transporting mechanism in the
heterojunction was explained, where three regions in I-V curve were appeared, that is to
say, three mechanism of current transportation through the manufactured heterojunction
in this research were eventually existed, the saturation current (IS) was found for each
region at different temperature (100, 200, 300) K.
Through C-V measurements we found built – in potential (Vbi), the donor
density (ND), the difference between Fermi level and conduction band (Ön), the
difference between Fermi level and valance band (Öp), the conduction and valence bands
discontinuity (DEC, DEV), and the depletion regions width (Xn, Xp) of heterojunction (n-
CdS/p-Ge) of the frequencies (1, 0.5) MHz.