Investigation on the oxide semiconductor SnO2, in the form of thin films, and coupling with graphene, aiming technological applications

Abstract

The work involves the deposition along with electrical and optical characterization of thin films in different steps. Step 1) Deposition of undoped SnO2 or doped with rare-earth ions, such as Eu or Er, which have high efficiency for optical emission. Step 2) Synthesis of hybrid structure composed of SnO2 / graphene and research on the electrical transport thermally and photo-excited, and measurement of optical properties. This knowledge is used to further application on gas sensor devices, as well as the possible application in optoelectronic devices, combining the transport in the graphene layer with the efficiency of rare earth emission in the SnO2 matrix. The rare-earth dopants to be used will be Eu3 +, for luminescence in the red, or Er3 + with emission in the near infrared. Measurements to be taken include: optical absorption in the UV-Vis and FTIR, photoluminescence, X-ray diffraction, electrical characterization as a function of temperature and excitation with monochromatic light; analysis via scanning electron microscopy and atomic force microscopy. Microscopy aims mainly to evaluate the interfaces substrate/SnO2, substrate/graphene and SnO2/graphene, as well as the surfaces of these layers. It will also be evaluated the longitudinal and transverse transport conditions in the built simple device. The main objective is the development of scientific and technological knowledge, and contribution to the making of electroluminescent devices and/or gas sensors.