| abstract |
A polymer comprising an electron-donating repeat unit of formula (I) and an electron-accepting repeat unit: -(A) n - (I) wherein A in each occurrence is independently a group of formula (II): Y in each occurrence is independently O or S. Z is O, S or NR 3 wherein R 3 is H or a substituent. R 1 in each occurrence is independently H or a substituent. R 2 in each occurrence is independently a substituent, n is at least 2. The polymer may be used as an electron-donating polymer in combination with an electron- accepting material in a bulk heterojunction layer of an organic photodetector. |