The energy distribution of the interface state density of SnO2/p-Si (1Â 1Â 1) heterojunctions prepared at different substrate temperatures by spray deposition method

We have fabricated the Al/SnO2/p-Si (1 1 1) Schottky diodes having the SnO2/p-Si heterojunction prepared using the spray deposition process at various Si substrate temperatures and report the first investigation of the energy distribution of the interface state density of these diodes. The barrier height ΦB estimated from the I-V and C-V measurements agrees with each other and increased with increasing substrate temperature. The energy distribution of interface state density Nss was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. The interface state density Nss of the diodes has an exponential growth with bias from the midgap towards the top of the valance band for each diode; for example, from 1.46 × 1012 eV−1 cm−2 in (0.46 − Ev) eV to 1.29 × 1012 eV−1 cm−2 in (0.53 − Ev) eV for SD3 sample.