Isomerization structure of photochromic diarylethene film based on electrical carrier injection

Photochromic films have attracted interest as an organic semiconductive memory material. Isomerization structures of a photochromic diarylethene (DAE) film induced by electrical carrier injection were investigated and were made clear for the coloring-reaction mode (CRM) and decoloring-reaction mode (DRM). Filaments consisting of the colored molecules in the colorless matrix were generated in the CRM, while random distribution of isomerized molecules occurred in the DRM. The ON-OFF ratio in current in the CRM was larger than that in the DRM. These results would be important for constructing organic semiconductor memory device using DAE.