TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Material: The substrate may comprise ceramics.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The substrate may comprise metals, or semiconductors.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The substrate may comprise metals, or semiconductors.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The polymer contains structural units comprising 1,4-phenylenes, 1,3-phenylenes, 1,2-phenylenes, 4,4'-biphenylenes, naphthalene-1,4-diyls, naphthalene-2,6-diyl, furan-2,5-diyls, 2,2'-bithiophene-5,5'-diyls, anthracenes-9,10-diyls, 2,1,3-benzothiadiazoles-4,7-diyls, N-substituted carbazole-3,6-diyls, N-substituted carbazole-2,7-diyls, dibenzosilole-3,6-diyls, dibenzosilole-2,7-diyls, N-substituted-phenothiazine-3,7-diyls, N-substituted-phenoxazines-3,7-diyls, dibenzothiophene-3,7-diyls, dibenzothiophene-2,8-diyls, dibenzofurane-3,7-diyls, dibenzofurane-2,8-diyls, indenofluorene-diyls, N,N,N',N'-tetraaryl-1,4-diaminobenzene-diyls, N,N,N',N'-tetraarylbenzidine-diyls, arylsilane-diyls, 9,9-spirofluorene-2,7-diyls, or preferably thiophene-2,5-diyl. The polymer contains structural units of a substituted fluorene-2,7-diyl of formula (I). The polymer contains structural units of a triarylamine-4,4'-diyl containing labile ester groups, of formula (II).R=4-30C hydrocarbyl; 3-30C hydrocarbyl containing S, N, Si, P, or O; or an aralkyl group and optionally S, N, Si, P, or O;R'=H; 4-30C hydrocarbyl; 3-30C hydrocarbyl containing S, N, Si, P, or O; or aralkyl and optionally S, N, Si, P, or O;R", R"'=alkyl, preferably Me, or H.Preferred Material: The substrate comprises plastics.    TECHNOLOGY FOCUS - TEXTILES AND PAPER - Preferred Material: The substrate may comprise paper. EXAMPLE - A copolymer of 9,9-di-n-octylfluorene and bithiophene (F8T2) was prepared by reacting an equimolar mixture of 5,5-dibromo-2,2'-bithiophene with 9,9-dioctyl-2,7-fluorene diboronate. A 1 wt.% solution of F8T2 in mesitylene was spin coated on a 100 mm IR grade double side polished silicon wafer. The wafer was dried for 20 minutes at 200degreesC under nitrogen. The resulting film had a thickness of approximately 90 nm. The wafer was cleaved into 1/2 inch strips for subsequent treatment. Thermal treatment of the wafer strips was carried out on a nitrogen purged hotplate at 400degreesC for 10, 20, and 40 minutes. The wafer strips were analyzed by FT4R. The intensity of aliphatic C-H absorption at 2923, 2854, and 1466 cm-1 decreased as a function of exposure time. The intensity of the absorption due to the aromatic carbon rings and to the thiophene rings did not change significantly. This indicated that the primary change in the structure of the polymer is loss of the aliphatic octyl groups with limited effect on the aromatic main chain.