Ladder-like metal oxide nanowires: Synthesis, electrical transport, and enhanced light absorption properties

Transparent metal oxide nanowires (NWs) have attracted intense research interest in recent years. We report here the synthesis of interesting ladder-like metal oxide NWs, including In₂O₃, SnO₂, ZnO, and Ga₂O₃, via a facile chemical vapor deposition (CVD) method. Their structural features and growth mechanism are demonstrated in detail by using the ladder-like In₂O₃ NWs as an example. Single ladder-like NW-based field-effect transistors (FETs) and photodetectors (PDs) of SnO₂ were fabricated in order to investigate their electrical transport and light absorption properties. Compared with straight NW-based FETs which operate in an enhancement mode (E-mode), FETs build on ladder-like NWs operate in a depletion mode (D-mode). The ladder-like NWs also give higher carrier concentrations than conventional single nanowires. Finite-difference time-domain (FDTD) simulations have been performed on the ladder-like NWs and the results reveal a great enhancement of light absorption with both transverse-electric (TE) and transverse-magnetic (TM) polarization modes, which is in good agreement with the experimental results.