Electrical characterization and modeling of Au/MEH-PPV/porous n+-GaAs/n+-GaAs heterojunction in direct and alternating current mode

• n-GaAs Porous substrates were fabricated by electro-chemical anodization.
• MEH-PPV thin layer were deposed on porous and straight n-GaAs by spin-coating.
• Each device's I–V and C–V were evaluated in dark and ambient conditions.
• Heterojunctions' energy band diagram at equilibrium was elaborated.
• Conductance and capacitance vs. frequency data was investigated.

Assembled heterojunction was fabricated by spin-coating poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene-vinylene)] (MEH-PPV) thin layers on straight and porous n+-GaAs substrates. The current–voltage and capacitance–voltage studies have shown an abrupt junction behavior with current conduction governed by SCLC and thermionic modes. Andersons' rules were used to determine depletion width and balance bands discontinuities for both heterojunctions. Capacitance and conductance vs. frequency techniques were used to evaluate the density of interface states. Density values obtained from both techniques were in a good agreement.