Effect of annealing on the electrical and interface properties of Au/PVC/n-InP organic-on-inorganic structures

• The electrical properties of Au/PVC/n-InP structure have been investigated.
• The Au/PVC/n-InP Schottky diode exhibits a good rectifying behaviour.
• A maximum barrier height is achieved after annealing at 100 °C.
• The interface state density is found to be 1.599 × 1012 eV−1 cm−2 for 100 °C annealed contact.
• Series resistance and interface state density have a significant effect on electrical properties.

In this work, a thin polyvinyl chloride (PVC) is deposited on n-type InP substrate as an interfacial layer for electronic modification of Au/n-InP Schottky structure. The atomic force microscopy (AFM) results show that there is no significant degradation in the surface morphology of the PVC Schottky contact even after annealing at 200 °C. The electrical parameters of Au/PVC/n-InP are calculated by current–voltage (I–V) and capacitance–voltage (C–V) techniques as a function of annealing temperature. Results show that the Au/PVC/n-InP structure exhibits an excellent rectifying behavior. The extracted barrier height (BH) of as-deposited Au/PVC/n-InP Schottky contact is 0.78 eV (I–V) and 0.87 eV (C–V). However, it is noted that the BHs increases to 0.85 eV (I–V) and 0.96 eV (C–V) upon annealing at 100 °C and then slightly decreases after annealing at 200 °C. Results indicate that the PVC film increases the effective barrier height by influencing the space charge region of the Au/n-InP junction. The series resistance of the Au/PVC/n-InP structure is extracted by Cheung’s method. The interface state density (Nss) as determined by Terman’s method is found to be 2.018 × 1012 and 1.599 × 1012 eV−1cm−2 for the as-deposited and 100 °C annealed Au/PVC/n-InP Schottky contacts, respectively. The experimental observations reveal that the Au/PVC/n-InP Schottky diode parameters change with increasing annealing temperature.

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