Surface photovoltage behavior of porous silicon modified with SO4 specimens

SO4 specimens modified surfaces of p-type porous Si (PS) is generated by electrochemical reactions of Si on surfaces with sulfuric acids in HF solution, which result in considerable change in the photovoltage property of PS. The reaction products at the porous Si surface are identified by Fourier-transform infrared (FTIR) spectroscopy, which implies that the interaction of HSO41− or SO42− ions with unpaired electrons at the surface of silicon under electrochemical condition may be responsible for the surface modification of PS.