Influence of Synthesis Route on the Radiation Sensing Properties of ZnO Nanostructures

R A Silva,M O Orlandi

doi:10.1155/2016/4054058

R A Silva, M O Orlandi

Open Access

https://doi.org/10.1155/2016/4054058

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Abstract

ZnO nanostructures were synthesized using two different routes and the light sensor response of structures was studied. The synthesis by carbothermal reduction resulted in ZnO tetrapods while the synthesis by microwave assisted hydrothermal method produced multipoint stars structures. Characterization by scanning and transmission electron microscopy confirmed that both structures consist of one-dimensional crystals with a hexagonal cross section and[001]growth direction. Under a simulated solar radiation spectrum, it was observed that tetrapods display a light sensor response of approximately 5000. For the multipoint stars, a maximum in the sensor signal value of 3400 was achieved, which also represents a substantial variation in the conductivity of the material. A model based on the surface oxygen presence is proposed to explain the observed results.

Highlights

The necessity for monitoring and the control of gas emission and ultraviolet (UV) radiation levels in the environment has been responsible for increasing the research and development of high performance sensor devices [1, 2]
The ZnO energy band gap corresponds to the energy of a photon in the ultraviolet range of spectrum, which indicates that this material is an excellent candidate for UV sensor devices [13]
The material morphology is mostly composed of tetrapods, which have at their extremities long strands and a diameter less than 100 nm

Summary

Introduction

The necessity for monitoring and the control of gas emission and ultraviolet (UV) radiation levels in the environment has been responsible for increasing the research and development of high performance sensor devices [1, 2]. Sensors based on nanostructured semiconductor materials have been widely investigated due to their high response signal, high efficiency, and low processing cost [3,4,5]. ZnO is an n-type semiconductor with theoretical band gap of 3.3 eV at room temperature and has several interesting properties: good transparency in the visible range of the electromagnetic spectrum, high electron mobility, piezoresponse, and luminescence, among others [10, 11]. The ZnO energy band gap corresponds to the energy of a photon in the ultraviolet range of spectrum, which indicates that this material is an excellent candidate for UV sensor devices [13]

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Conclusion