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 × 1012 cm−2 eV−1 and 1.68 × 10−3 s in (0.73-Ev) eV to 1.80 × 1012 cm−2 eV−1 and 5.29 × 10−5 s in (0.43-Ev) 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-Ev) eV towards (0.73-Ev) eV.