|Title||Suppressing crystallization in solution-processed thin films of organic semiconductors|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||J.B. Sherman, C.Y. Chiu, R. Fagenson, G. Wu, C.J. Hawker, and M.L. Chabinyc|
Glassy organic semiconductors provide a convenient host for dispersing guest molecules, such as dopants or light-emitting chromophores. However, many glass-forming compounds will crystallize over time leading to changes in performance and stability in devices. Methods to stabilize amorphous molecular solids are therefore desirable. We demonstrate that solution-processable glasses can be formed from a mixture of 8,8'-biindeno[2,1-b] thiophenylene (BTP) atropisomers. While the trans isomer of methylated BTP, (E)-MeBTP crystallizes in spin-cast films, the addition of (Z)-MeBTP slows the growth of the spherulites. X-ray scattering and optical microscopy indicate that films containing 40% (Z)-MeBTP do not crystallize, even with the addition of nucleation agents and aging for several months.