TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Arrangement: Electrode (11) is a transparent electrode and electrode (12) is a counter electrode. The work function of electrode material of electrode (11) is smaller than the work function of electrode material of electrode (12).    TECHNOLOGY FOCUS - POLYMERS - Preparation: No general preparation given. Preferred Unit: The conjugated polymer consists of an acceptor unit and a donor unit coupled alternately. The acceptor unit contains partial structure (I). Donor units (I,II,III) are connected with the donor unit group linearly sequentially. Donor units (I,III) contain thiophene partial structure(s) of formula (II), preferably bithiophenyl partial structure of formula (III). Donor unit (II) does not contain partial structure (II). Among partial structure (II), at least one of R3 and R4 is 8-20C branched alkyl in one structure, and H or 1-7C linear alkyl in other structure. Among partial structure (III), at least one of R3-R6 is 8-20C branched alkyl in one structure, and H or 1-7C linear alkyl in other structure.R3-R6=H or 1-20C alkyl. Preferred Definitions:    R1,R2=optionally substituted biphenyl-2,2'-diyl.    EXAMPLE - In a nitrogen-substituted 100-ml flask, (in g) 5,6-difluoro-4,7-diiodo-benzo(1,2,5)thiadiazole (4.2) was dissolved in methanol (50 ml). Sodium borohydride (3.8) was added to the obtained solution and stirred at room temperature for 24 hours. After separating the insoluble matter by filtration from the reaction liquid and concentrating the mother liquid under reduced pressure, 4,5-difluoro-3,6-diiodo-benzene-1,2-diamine (2) was obtained by purifying. The obtained compound (3.9) was dissolved in acetic acid (20 ml). 9,10-Icosane dione (3) was added to the obtained solution and stirred at 100 degrees C for 24 hours. After concentrating the reaction liquid under reduced pressure, 6,7-difluoro-5,8-diiodo-2,3-dioctylquinoxaline (3) was obtained by purifying the obtained solid. The obtained compound (0.64) and 7,7-dioctyl-4,10-bis(trimethylstannyl)-3,11-dithia-7-silatricyclo(6.3.0.02,6)undeca-1(8),2(6),4,9-tetraene (0.74) were dissolved in toluene (20 ml) bubbled and deaerated with nitrogen gas. Tetrakis triphenylphosphine palladium (0.12) was added to the obtained solution and heat-refluxed for 20 hours. The reaction liquid was cooled to room temperature vicinity after completion of reaction and reprecipitated by addition of methanol (200 ml). The deposit was dissolved in chloroform and filtered to remove insoluble matter. The product was purified using chloroform solution. The obtained chloroform solution was concentrated under reduced pressure and reprecipitated using methanol (200 ml). The precipitate was dried under reduced pressure to obtain a conjugated polymer (0.12) of formula (IA). The polymer had a weight average molecular weight of 29000 and a polydispersion degree of 1.8.    n=not defined.    N.B: n is not defined.