Photoelectron spectroscopy study of the interactions between ErF3 dopants and Alq3 hosts for near-infrared organic light-emitting diodes.

Highlights: [•] We have demonstrated the chemical reaction, charge and energy transfer process using photoelectron spectroscopy for near-infrared organic light-emitting diodes. [•] Based on the result of this paper, we can achieve the optimal device efficiency by certain of ErF3 dopant concentration, which is useful for the research of NIR-OLED. [•] The study on the electroluminescence mechanism is crucial for the applying of ErF3 doped NIR-OLED. [Copyright &y& Elsevier]