The electrical characteristics of Sn/methyl-red/p-type Si/Al contacts

The junction characteristics of the organic compound methyl-red film (2-[4-(dimethylamino)phenylazo]benzoic acid) on a p-type Si substrate have been studied. The current–voltage characteristics of the device have rectifying behavior with a potential barrier formed at the interface. The barrier height and ideality factor values of 0.73 eV and 3.22 for the structure have been obtained from the forward bias current–voltage ( I– V) characteristics. The interface state energy distribution and their relaxation time have ranged from 1.68 × 10 12 cm −2 eV −1 and 1.68 × 10 −3 s in (0.73- E v) eV to 1.80 × 10 12 cm −2 eV −1 and 5.29 × 10 −5 s in (0.43- E v) eV, respectively, from the forward bias capacitance–frequency and conductance–frequency characteristics. Furthermore, the relaxation time of the interface states shows an exponential rise with bias from (0.43- E v) eV towards (0.73- E v) eV.