Ανάπτυξη Χημικών Αισθητήρων Και Βιοαισθητήρων Σε Ετεροδομές Και Νανοδομές III-νιτριδίων

Abstract

Chemical sensors are significant analytical instruments used for the determination of a wide variety of analytes. In comparison with other analytical methods, chemical sensors excel mainly because of their ability to monitor the analyte continuously and without destroying the sample. Additionally, due to their small size, they can be easily incorporated in automated systems, such as continuous flow systems, and perform real-time monitoring. These characteristics are very important since they account for the use of chemical sensors in field analysis and in vivo monitoring. Because of that, up to now, chemical sensors have been implemented in food and water quality control, in medical diagnosis, in environmental monitoring e.t.c. Still, the applications and the interest in the market of analytical instruments are continuously increasing, revealing the intense research activity in the field which is directly related with the great significance of chemical sensors in instrumental analysis. The use of new materials for the development of chemical sensors with improved or novel characteristics is one of the main research activities in the field. In this framework, new semiconductor materials have been studied in the last few years, for the development of chemical sensors, including the group of III-nitrides. These materials are mainly used for the development of high power and high frequency electronic devices, while they are also used in optoelectronics, since they are the only semiconductors that emit light in the blue and ultraviolet region of the spectrum. Moreover, in the last few years, this group of semiconductor materials, due to their excellent chemical inertness and also mechanical and thermal stability, has attracted great interest for their use in the development of chemical sensors. The scope of this project is to explore the use of planar and nanostructured III-nitride crystals for the development of chemical sensors and biosensors. More specifically, in addition to the most extensively studied +c-plane GaN, it is aimed to expand the research to different crystal directions, such as the non polar a-plane GaN, and to other III-nitride materials, such as the InN and InGaN Abstract 2 alloys. Moreover, the use of III-nitride nanocolumns for the development of chemical sensors and biosensors is also explored for the first time.In more detail, the first part of this work concerns a comparison study case. This advantage, along with the superior optical properties of the III-nitride nanocolumns, make these materials very promising candidates for the development of novel and more sophisticated biosensors.