A photochromic diode with a continuum of intermediate states: towards high density multilevel storage.

A continuum of intermediate states (current levels) is demonstrated for an organic diode utilizing a photochromic (dithienylethene) switching layer. Specific intermediate states can be attained by controlling the fraction of closed isomer (X) in the transduction layer, affording a novel methodology for multilevel storage applications. The analog response of the device is discussed in terms of the concentration and morphology of closed dithienylethene isomer, which can be accessed via optical and electrical switching reactions.