title: Morphological evolution of silver nanoparticles and its effect on metal-induced chemical etching of silicon.
abstract: In this report, we have demonstrated the morphological evolution of the silver nanoparticles (AgNPs) by controlling the growth conditions and its effect on morphology of silicon (Si) during metal-induced electroless etching (MICE). Self-organized AgNPs with peculiarly shape were synthesized by an electroless plating method in a conventional aqueous hydrofluoric acid (HF) and silver nitrate (AgNO3) solution. AgNP nuclei were densely created on Si wafer surface, and they had a strong tendency to merge and form continuous metal films with increasing AgNO3 concentrations. Also, we have demonstrated that the fabrication of aligned Si nanowire (SiNW) arrays in large area of p-Si (111) substrates by MICE in a mixture of HF and hydrogen peroxide (H2O2) solution. We have found that the morphology of the initial AgNPs and oxidant concentration (H2O2) greatly influence on the shape of the SiNW etching profile. The morphological results showed that AgNP shapes were closely related to the etching direction of SiNWs, that is, the spherical AgNPs preferred to move vertical to the Si substrate, whereas non-spherical AgNPs changed their movement to the [100] directions. In addition, as the etching activity was increased at higher H2O2 concentrations, AgNPs had a tendency to move from the original [111] direction to the energetically preferred [100] direction.
authors.affiliation: Green Energy Research, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 50-1,Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun, Daegu 711-873, Republic of Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Baek
authors.forename: Bo Hyun
authors.initials: BH
authors.lastname: Kong
authors.forename: Hyung Koun
authors.initials: HK
authors.lastname: Cho
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Kim
mesh_terms: D003460:Crystallization / Q000379:methods*; D006858:Hydrofluoric Acid / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D054802:Molecular Imprinting / Q000379:methods*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D012834:Silver; D006858:Hydrofluoric Acid; D012825:Silicon