Ultraviolet detection from graphitic-C/Zn1-xMgxO Schottky devices fabricated at moderate temperatures

Ultraviolet (UV) Schottky detector devices were fabricated on polycrystalline wurtzite Zn1-xMgxO films energetically deposited onto a=plane sapphire at room- temperature (RT) and 200 degrees C. The unintentionally doped, transparent, n-Zn1-xMgxO films exhibit low surface roughness (<5% of film thickness), moderate carrier concentration, and Hall mobility up to 15 cm(2) V-1 s(-1). The direct bandgaps of the RT and 200 degrees C films (x =0.24 and x =0.20) were 3.57 eV and 3.40 eV. Schottky diodes with graphitic anodes formed on these films exhibited barrier heights up to 0.88 eV and ideality factors as low as 1.97. Spectral response measurements demonstrated UV/visible photo-current ratios up to similar to 10(4)