High-quality CdTe nanowires: Synthesis, characterization, and application in photoresponse devices

Abstract

High-quality straight and multiply kinked CdTe nanowires (NWs) were synthesized by the facile chemical vapor deposition method at 600 °C. The as-synthesized NWs were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, and photoluminescence (PL) spectroscopy. The straight CdTe NWs have single crystalline zinc blende structure with growth direction along the ⟨111⟩ direction. Their PL spectra consist only sharp near band edge emission around 824.3 nm. The multiply kinked CdTe NWs contain one or more fixed (∼125.2°) angle joints; each arm of the kinked NWs is single crystalline with similar selected area electron diffraction pattern as that of the straight CdTe NWs. The two growth directions in the multiply kinked CdTe NWs are ⟨200⟩ and ⟨111⟩. Single straight and kinked CdTe NW photoresponse devices were fabricated and testified to have high photocurrent decay ratio, high responsivity, fast response time, and no decay tail under 633 nm He–Ne laser illumination. These straight and multiply kinked CdTe NWs may open up potential applications in the bottom-up integrated nanoelectronic and nanophotonic systems, such as photovoltaic and multiterminal nanodevices etc.