| AVS 64th International Symposium & Exhibition | |
| Surface Science Division | Thursday Sessions |
| Session SS+AS+EM-ThA |
| Session: | Semiconductor Surfaces |
| Presenter: | Meixi Chen, University of Delaware |
| Authors: | M. Chen, University of Delaware J.H. Hack, University of Delaware A. Iyer, University of Delaware R.L. Opila, University of Delaware |
| Correspondent: | Click to Email |
Iodine and Quinhydrone(QHY) dissolved in methanol have long been known to react with hydrogen terminated silicon surfaces to passivate electronic defects where photo-excited carriers recombine non-radiatively. The mechanism of this passivation is not well understood. The two constituent parts p-benzoquinone(BQ) and hydroquinone(HQ) have been studied separately in this work. We have shown that even though BQ and HQ are a redox couple, they behave very differently in reacting with silicon surfaces. The reaction is photolysis, pH sensitive and solvent-dependent. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry were used to show that the BQ reacted with the surface. The electrical passivation of silicon surfaces is confirmed by carrier lifetime measurements where the silicon surface recombination velocity is deceased to 11cm/s. Changes in surface band bending are observed in XPS surface photovoltage. DFT calculations have also been performed. The reaction mechanism will be discussed in detail.