Abstract
The self-assembled monolayers (SAMs) of aniline and alkyl substituted anilines grafted on n-Si (111) crystalline surface were prepared in the presence of lauroyl peroxide, and the photoelectrodes of polyanilines/n-Si (111) crystalline were prepared based on polymerizations between the SAMs and anilines. Additionally, the polyanilines with sulfonic acid group (SPANI) substituted n-Si(111) crystalline photoelectrodes were prepared via the above samples to fabricate SPANI/n-Si (111) electrodes (Si-SPANIs). Electrochemical studies indicate that the electrode based on 4-bromoaniline (Si-PANI) is better than that of 4-ethynylaniline (Si-C =C-PANI), and the electrode from 4-vinylaniline (Si-C-C-PANI) is the poorest. In addition, anion ring substitution is important in promoting photoelectric conversion of the electrodes. An electrode with high photocurrent density of 15.4 mA · cm-2 and photoelectric transformation efficiency of 13% was obtained.