Figure 3.
Influence of surface trap states on oxygen molecule adsorption, charge transfer, and band bending within a nanowire. (a) Photoexcitation increases nanowire free carrier density and conduction, which are reduced (b) by oxygen molecule adsorption, increased band bending, and reduced carrier density inside the wire. (c) Above band gap excitation of the O2—adsorbed wire reduces band bending as additional free carriers recombine with trapped surface charge and O2 molecules desorb. With permission from [26]. Copyright 2007 American Chemical Society.