Influence of polymer coating on the low-temperature photoluminescence properties of ZnO nanowires

Abstract

We report on low temperature photoluminescence studies of ZnO nanowires embedded in different polymers. Comparing the spectra of as-grown and embedded ZnO nanowires, we find a decrease of the deep-level emission and an increase of the near band-edge emission after the embedding process. The near band-edge emission of the embedded ZnO nanowires is dominated by a surface exciton band. The observed effects are independent of the selected polymer. The decrease of the deep-level emission scales with the balling abilities of the different polymers. We propose a model to explain the spectral changes.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…Studies have shown that annealing at 200 °C can largely reduce the defect concentration as evidenced by positron annihilation spectroscopy [349]. A polymer coating on the ZnO nanowires was also demonstrated to effectively depress the defect emission and enhance the near-band-edge emission [358]. A photoluminescence spectrum of ZnO nanowires at 4.2 K is shown in Fig.…”

Nanoscale transport of surface excitons at the interface between ZnO and a molecular monolayer

“…SX PL has been detected from nanostructures at low temperature [9][10][11], and from ZnO bulk single crystals or epitaxial layers [8,12]. Recently, we have observed a distinct SX PL band from a ZnO thin film covered with a molecular monolayer [12].…”

“…Different types of excitons have been distinguished in the prototype wide gap semiconductor ZnO: free excitons (FX) with a binding energy of ~60 meV, excitons bound to different donor and acceptor atoms (DX), and surface excitons (SX) [5][6][7][8][9][10][11][12]. SX PL has been detected from nanostructures at low temperature [9][10][11], and from ZnO bulk single crystals or epitaxial layers [8,12].…”

Guard Cell and Tropomyosin Inspired Chemical Sensor

“…The biologically-inspired chemical sensor design utilizes available materials in a unique way to form a simple and elegant design. Considering manufacturability, the nanowires connected at both ends to a substrate (Figure 9a) could most likely utilize conventional microelectronic assembly and then be suspended into different polymer solutions [83] or use a polymer chemical vapor deposition technique [84] to coat the nanosprings. Further investigation is necessary to determine if the sensor elements suspended between two grids could be fabricated on the nano-scale.…”