Analytical model of Energy Level Alignment at Metal-Organic Interface facilitating Hole Injection

An analytical description of energy level alignment at metal-organic interface based on a detailed electrostatic model and exponential density of states is presented here. The calculated alignment between the Fermi energy of electrode and the organic transport energy shows good quantitative agreement with the proposed numerical electrostatic model and experimental data, indicating that the analytical model can well describe the material disorder and carrier density. More important, the simulations highlight that the electrode with high effective work functions and the organic material with large dielectric constant can facilitate the hole injection from metal to organic. Finally, the Gaussian distribution density of states has compare to the exponential model, confirmed the accuracy of the analytical description for energy level alignment.