Optical and charge transport properties of DI‐n‐hexyl substituted polysilylene and polygermylene

Optical and charge transport properties of poly(di‐n‐hexylsilylene), PD6S, and poly(di‐n‐hexylgermylene), PD6G, have been studied. The main‐chain σ‐conjugation in both polymers leads to intense σ‐σ* UV‐absorptions. A hypsochromic shift is observed for both polymers at the transition from a crystalline solid phase to a columnar mesophase. This transition is accompanied by disordering of the polymer backbone which results in a decrease of the radiation induced microwave conductivity by a factor of 26 for PD6S and a factor of 4 for PD6G. In the disordered mesophase a charge carrier mobility of ca. 0.6×106 m2/Vs is found for both polymers. Charge carrier mobilities of 15×106 m2/Vs and 2.4×10‐6.m2/Vs are found in the crystalline phase of PD6S and PD6G respectively, indicating a more ordered backbone for PD6S compared with PD6G.