We have investigated the effect of surface dangling bonds and molecular passivation on the doping of GaAs nanowires by first-principles calculations. Results show that the positively charged surface dangling bond on G...We have investigated the effect of surface dangling bonds and molecular passivation on the doping of GaAs nanowires by first-principles calculations. Results show that the positively charged surface dangling bond on Ga atom is the most stable defect for both ultrathin and large size GaAs nanowires. It can form the trap centers of holes and then prefer to capture the holes from p-type doping. Thus it could obviously reduce the efficiency of the p-type doping. We also found that the NO2 molecule is electronegative enough to capture the unpaired electrons of surface dangling bonds, which is an ideal passivation material for the Zn-doped GaAs nanowires.展开更多
基金This work was supported by the National Basic Research Program of China （No.2010CB327600）, the National Natural Science Foundation of China （No.61020106007 and No.61376019）, the Natural Science Foundation of Beijing （No.4142038）, the Specialized Research Fund for the Doctoral Program of Higher Education （No.20120005110011）, and the 111 Program of China （No.B07005）. Jian-gong Cui would like to thank Dr. Xin Yan and Dr. Jun-shuai Li from Beijing University of Posts and Telecommunications for useful discussions.
文摘We have investigated the effect of surface dangling bonds and molecular passivation on the doping of GaAs nanowires by first-principles calculations. Results show that the positively charged surface dangling bond on Ga atom is the most stable defect for both ultrathin and large size GaAs nanowires. It can form the trap centers of holes and then prefer to capture the holes from p-type doping. Thus it could obviously reduce the efficiency of the p-type doping. We also found that the NO2 molecule is electronegative enough to capture the unpaired electrons of surface dangling bonds, which is an ideal passivation material for the Zn-doped GaAs nanowires.
