Three-dimensional hybrid inorganic/organic optoelectronics based on GaN/oCVD-PEDOT structures

We report on 3D micro-LEDs consisting of a nitride-based core and a p-doped PEDOT polymer shell. The doped polymer shell is deposited from the gas phase using oxidative chemical vapor deposition (oCVD). oCVD can be directly integrated with state-of-the-art semiconductor processing technologies and allows for a gentle deposition from the gas phase at moderate vacuum conditions and temperatures below 150°C. We characterize the electrical properties of the hybrid organic/inorganic interface with temperature-dependent current-voltage measurements. Applying a Schottky model, we identify thermionic emission of electrons as the dominant conduction mechanism across the heterojunction and extract a mean barrier height of 1.4 eV with an ideality factors as low as 2.0 at room temperature indicating a low defect density at the interface. The results give a conclusive picture of the chances of oCVD-PEDOT/nitride heterojunctions for the use in 3D micro-LEDs.