Tuning of ZnO 1D nanostructures by atomic layer deposition and electrospinning for optical gas sensor applications.

We explored for the first time the ability of a three-dimensional polyacrylonitrile/ZnO material-prepared by a combination of electrospinning and atomic layer deposition (ALD) as a new material with a large surface area-to enhance the performance of optical sensors for volatile organic compound (VOC) detection. The photoluminescence (PL) peak intensity of these one-dimensional nanostructures has been enhanced by a factor of 2000 compared to a flat Si substrate. In addition, a phase transition of the ZnO ALD coating from amorphous to crystalline has been observed due to the properties of a polyacrylonitrile nanofiber template: surface strain, roughness, and an increased number of nucleation sites in comparison with a flat Si substrate.

Evolution of microstructure and related optical properties of ZnO grown by atomic layer deposition.

A study of transmittance and photoluminescence spectra on the growth of oxygen-rich ultra-thin ZnO films prepared by atomic layer deposition is reported. The structural transition from an amorphous to a polycrystalline state is observed upon increasing the thickness. The unusual behavior of the energy gap with thickness reflected by optical properties is attributed to the improvement of the crystalline structure resulting from a decreasing concentration of point defects at the growth of grains.