Small organic molecule chromophores containing a benzo[c][1,2,5]thiadiazole with an electron-withdrawing substituent W in the 5-position (5BTH), benzo[c][1,2,5]oxadiazole with an electron-withdrawing substituent W in the 5-position (5BO), 2H-benzo[d][1,2,3]triazole (5BTR) with an electron-withdrawing substituent W in the 5-position (5BTR), 5-fluorobenzo[c][1,2,5]thiadiazole (FBTH), 5-fluorobenzo[c][1,2,5]oxadiazole (FBO), or 5-fluoro-2H-benzo[d][1,2,3]triazole (FBTR) core structure are disclosed. Such compounds can be used in organic heterojunction devices, such as organic small molecule solar cells and transistors.