Abstract:
The electrical and photoresponse properties of
an Al/p-Si/organic layer/Al diode were investigated. The
organic layer containing novel 2,2-bis[spiro(7,8-dioxy-
4-methylcoumarin)]-4,4,6,6-bis[spiro(2’,2”-dioxy-1’,1”-
biphenylyl)]cyclotriphosphazene compound was coated by
the drop casting method on p-Si having ohmic contact. The
structural characterization of the novel cyclotriphosphazene
compound was confirmed by using 1H, 13C and 31P-NMR,
elemental analysis and FTIR spectroscopic techniques. The
diode exhibits a photoconducting and photodiode behavior
under solar light illumination. The electrical parameters
such as ideality factor, barrier height and series resistance
of the diode were determined from I-V characteristics. It
is seen that the photocurrent of the diode under illumination
is higher than the dark current. Also, the frequency
dependence of capacitance (C) and conductance (G) was
explained on the basis of interface states. It is evaluated that the hybrid photodiode can be used as a photosensor in
organic photodetector applications.