The Study of Electrical Properties and Photocurrent of Polyaniline/ fluorescein films

Abstract

Electrical conductivity and visible photo current (PC) measurements have been
performed on thick film (10 μm) of polyaniline modified with (1x10^-4)
fluorescein organic dye were all measurements have been made using Sandwich structure
of aluminum and semitransparent aluminum with area (0.03 cm²) circular electrode. The
D.C. conductivity was measured as a function of doping ratio with iodine using the
technique of two probes.All current measurements have been made at steady state
conditions were the obtained results showed that the domain conduction mechanisms was
identified as space charge limited current (SCLC) and the D.C. bulk conductivity of pure
films was 6.6x10^-9S.cm^-172mole) content of ,and this conductivity is increased by 5.4 times of films with
doping ratio equal to 2% . Photocurrent (PC) was measured with specified wave length
as a function of applied voltage were the intensity of the incident light was 295 lux/m
for each case. The obtained results of PC showed that the observed photons form excites, and
the caste films have poor photoconductivity while maximum peak of D.C. conductivity
under illumination was obtained near Yellow region of visible light were the absorption of
incident light is high and free carriers are available.
Also the obtained results showed that the cut-off wave length is near red region, and the
recombination process is bulk finally Another noticeable remark, that the photocurrent is
increased by amount of 800 times & D.C conductivity is increased by 1300 comapred to
magnitude at darkness.