ZnO nanorods are promising materials for many applications, in particular for UV detectors. In the present paper, the properties of high crystal quality individual ZnO nanorods and nanorod arrays grown by the self-catalytic CVD method have been investigated to assess their possible applicationsfor UV photodetectors. X-ray diffraction, Raman spectroscopy and cathodoluminescence investigations demonstrate the high quality of nanorods. The nanorod resistivity and carrier concentration in dark is estimated. The transient photocurrent response of both as grown and annealed at 550 °C nanorod array under UV illumination pulses is studied. It is shown that annealing increases the sensitivity and decreases the responsivity that is explained by oxygen out-diffusion and the formation of near surface layer enriched with oxygen vacancies. Oxygen vacancy formation due to annealing is confirmed by an increase of green emission band intensity.

Zinc oxide is a promising material for the creation of various types of sensors, in particular UV detectors. In this work, arrays of ordered nanorods were grown by chemical vapor deposition. The effect of environmental humidity on the sensing properties of zinc oxide nanorod arrays was investigated, and a prototype UV sensor using indium as an ohmic contact was developed. UV photoresponses were measured for the samples stored in dry and wet atmospheres. The increase in sensitivity and response of the ZnO nanorod arrays was observed after prolonged exposure to a wet atmosphere. A model was proposed to explain this effect. This is due to the formation of hydroxyl groups on the surface of zinc oxide nanorods, which is confirmed by FTIR spectroscopy data. For the first time, it has been shown that after storage in a wet atmosphere, the sensory properties of the structure remain stable regardless of the ambient humidity.

The electrical properties of individual ZnO nanorods were investigated. Chemical vapor deposition was used to grow arrays of ordered ZnO nanorods on silicon substrates. A 3D manipulation system was used to separate individual nanorods. Then, these were transferred to interdigital platinum electrodes and welded together by means of an ion beam. The ohmic nature of the contact between platinum and zinc oxide was confirmed by electrical measurements. The high quality of the material was confirmed by studying the cathodoluminescence spectrum of these nanorods. A possibility of the diffusion length estimation in nanorods with ohmic contacts from the electron beam induced current measurements is demonstrated. It is shown that in ZnO nanorods grown by chemical vapor deposition, the diffusion length can reach values up to 2 μm. This value is a few times higher than the data available in the literature that confirm the low defect content in such nanorods.

Zinc oxide is one of the most promising materials used to create devices in the ultraviolet (UV) range. In this article, we study the sensor properties of ordered ZnO nanorod arrays grown by chemical vapor deposition. The possibility of their use as an indicator of UV radiation to control the dose of UV radiation, both from natural and artificial light sources, is assessed. The X-ray diffraction, Raman spectroscopy (RS), and cathodoluminescence (CL) data demonstrate the high quality of nanorods. Based on the ZnO nanorod array, a sensor prototype was fabricated based on the change in ZnO conductivity under the UV irradiation. A comparison of the response of such a sensor with the readings of a UV radiometer showed a high correlation.

The optical properties of high-quality zinc oxide nanorods grown by the self-catalytic CVD method are considered. The effect of irradiation of an array of nanorods by a low-energy electron beam at 85 K on UV luminescence has been demonstrated. It is shown that such irradiation does not change the spectra form at both room and liquid nitrogen temperatures and only affects the emission intensity. The pronounced difference in cathodoluminescence spectra for nanorods with different morphology was observed at 85 K. However, the deconvolution of spectra using Gaussian curve fitting shows that in spite of noticeable difference, all spectra consist of the same set of emission bands similar to those previously observed in ZnO. The nanorod geometry only affects the relative contribution of the emission bands to the full spectrum. The possible nature of emission bands measured in ZnO nanorods is discussed.

Miniaturization of devices based on one-dimensional semiconductor nanocrystals is of high importance for high-frequency applications, photonics, and various sensors. Zinc oxide, one of the materials actively studied for such purposes, can be obtained by several technologies. Among them, chemical vapor deposition is distinguished by a low concentration of defects in the resulting structures. The aim of this work was to fabricate a test device on a single ZnO nanocrystal by means of nanomanipulation and to study its spectral response in the range from near-IR to UV. Since one of the promising applications of ZnO is UV sensors, the task was to test the selectivity of the response to the wavelength range below 400 nm.