Mechanism of charge transport in hybrid organic–inorganic PEDOT:PSS/silicon heterojunctions

Temperature- and voltage-dependent measurements show that current in polymer–silicon junctions follows different physics in each bias direction.

• Reverse bias: current is injection-limited by a quasi-Schottky barrier at the interface.
• Forward bias: space-charge-limited current through the PEDOT:PSS layer, trap-limited at low bias.
• Trap density about 5.6 × 10¹⁵ cm⁻³ with characteristic energy about 0.107 eV.
• The double-logarithmic forward characteristic marks a transition from the Mark–Helfrich to the Mott–Gurney regime.