Abstract:
In this Letter, we report the effects of ammonium sulfide
[(NH4)2S] surface treatment on electrical and optical charac teristics of the electrodeposited n-type Cu2O thin films on Ti
substrates. Films characterized structurally and morphologi cally before and after the surface treatment were compared
using conductivity, spectral photoresponse and current–
voltage (I–V) measurements. The ammonium sulfide surface
treatment time showed an impact on optical and electrical
characteristics of the films. Treated Cu2O films exhibited en hanced conductivity giving rise to a 50-fold increase in the
photocurrent and improved I–V characteristics. It was found
that the sulfur passivation resulted in a nearly ohmic behav iour for Au or Ni contacts made with n-type Cu2O whereas
Ag or Cu contacts showed nearly Schottky behaviour. The re sults showed that ammonium sulfide treatments were very
effective to passivate defects and improve the optical and
electrical properties of polycrystalline n-type Cu2O thin films
that may provide a solid platform for Cu2O based devices of
enhanced quality.
