NOVELTY - Material comprises: either conjugated molecules, and for each conjugated molecule, a side chain bonded to the conjugated molecule and including at least one of a siloxane-terminated unit and a derivative of a siloxane-terminated unit configured and arranged to enhance solubility of the conjugated molecule and to set pi -stacking distance between the conjugated molecules that facilitate carrier mobility between the conjugated molecules; or a solubilizing side chain including a linear aliphatic chain and a siloxane-terminated unit (A).    USE - (I) is useful in an apparatus (claimed) including electronic devices, field-effect transistors, organic solar cells, memory devices, organic light-emitting devices, organic transistor sensors, chemical sensors, biological sensors, pressure sensors, and doped conductors.    ADVANTAGE - (I) provides apparatus has improved flexibility or stretchability.    DETAILED DESCRIPTION - Material (I) comprises: either conjugated molecules, and for each conjugated molecule, a side chain bonded to the conjugated molecule and including at least one of a siloxane-terminated unit and a derivative of a siloxane-terminated unit configured and arranged to enhance solubility of the conjugated molecule and to set pi -stacking distance between the conjugated molecules that facilitate carrier mobility between the conjugated molecules; or a solubilizing side chain including a linear aliphatic chain and a siloxane-terminated unit of formula(A). INDEPENDENT CLAIMS are included for:    (1) an apparatus comprising first and second conductive terminals, and an organic semiconductor film electrically coupled to pass carriers between the conductive terminals, where the organic semiconductor film includes the material; and    (2) a method comprising bonding solubilizing side chains to the conjugated molecules, where each side chain includes at least one of a siloxane-terminated unit and a derivative of a siloxane-terminated unit, and forming a solution in a solvent by solubilizing side chains to increase solubility of the conjugated molecules in the solvent.