Structure Function Paradigms of Organic Electrooptic Materials

Thesis (Ph.D.)--University of Washington, 2016-03Organic Electrooptic Materials have been demonstrated and commercialized as active com- ponents in telecommunications systems. Application of organic materials to electrooptic switching devices could result in large gains in terms of size weight and power figures of merit. This is because organic materials exhibit large electrooptic coefficients, ultra-fast femto-second response times, submicron chipscale integration, and highly tunable absorp- tion via synthetic manipulation of the sp2 hybridized π system responsible for electroopic response; however, due in part to deficiencies in thermal stability and preferential non- centrosymmetric bulk-phase ordering, these materials have not been able to overcome engi- neering barriers to realize their full potential. This work approaches the problem of thermal stability by invoking structure function paradigms of organic materials and re-engineering ex- isting molecular structures with large electrooptic response for improved device performance. Incremental changes in molecular structure are observed to have significant effects on glass transition temperature, poling efficiency, maximum electrooptic coefficent, and device con- ductance, with minimal changes in optical properties in the bulk phase. A notable increase in glass transition temperature with no significant reduction in electrooptic response is ob- served. [1] Solid-state device engineering concepts to eliminate unwanted current during the poling process are presented with experimental evidence to support the efficacy of reducing current, and thus increasing the electric field, during poling. [2] Real device measurements are also included to demonstrate the full potential of state-of-the art materials. [3