Crystal structure analysis of self-catalyzed InAs nanowire grown by MOCVD

We studied the crystal structure of self-catalyzed InAs nanowires with different diameters grown on Si Substrate by metal-organic chemical vapor deposition (MOCVD) and found that oxidation degree and nanowire diameter directly affect the lattice structure of InAs nanowire. In the non-oxidized state of InAs nanowires, when the diameter is greater than 160nm, the lattice structure is mainly cubic zinc blende (ZB) structure. When the diameter is between 121nm and 80nm, ZB structure and hexagonal wurtzite (WZ) structure coexist. When the diameter is less than 66nm, the lattice structure is mainly WZ structure. In the fully oxidized state of InAs nanowires, a stable layer of In2O3 is formed on its surface, and InAsO4 will be formed inside due to infiltrated oxygen atoms. When InAs nanowires are made into nanoelectronic devices as the core material, if oxidation is not prevented, InAs material with excellent electrical conductivity will also become InAsO4.