Electrical conduction and photodiode properties of Au/Feq3/p-Si/Al hybrid heterostructure

Thin films of iron tris(8-hydroxyquinoline) (Feq3) are prepared on p-Si substrates by thermal deposition under high vacuum. The current-voltage (I-V) curves of Au/Feq3/p-Si/Al heterojunction are recorded as a function of temperature range from 303 to 383 K at 20 K interval. The device shows rectification behavior, with room temperature ideality factor (n) and barrier height (ϕ) values of 2.30 and 0.81 eV, respectively. The temperature dependence of ϕ and n is explained in terms of barrier inhomogeneity, in which the homogenous ϕ value is estimated as 0.97 eV. The conduction mechanisms of the diode are determined and related parameters are evaluated The series resistance of the diode is estimated as a function of temperature. Up on illuminating the diode, the reverse current of the diode increases with increasing the impinging light intensity, from which the photosensitivity and photoconduction are determined.