Characterization of component segregation in co-deposited glasses of TCTA and Ir(ppy)₃

Glasses of organic semiconductors produced by physical vapor deposition (PVD) have shown exceptional properties, such as high stability and control of molecular orientation. However, previous studies have focused on single component systems, and less is known about multi-component PVD glasses. In this work, we characterized co-deposited glasses of Ir(ppy)₃ and TCTA by varying the mass ratio and deposition temperature. Grazing incidence wide angle X-ray scattering (GIWAXS) was performed to detect the component segregation. With 10% Ir(ppy)₃, the molecules were well dispersed in the co-deposited glasses, while 30% Ir(ppy)₃ glasses had large domains based on the analysis of the characteristic anisotropic peak that pure Ir(ppy)₃ forms. Furthermore, differential scanning calorimetry (DSC) experiments showed that all co-deposited glasses have high kinetic stability compared to liquid-cooled glasses.