| AVS 54th International Symposium | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Aspects of Thin Films Poster Session |
| Presenter: | J.D. Peak, University of Tennessee |
| Authors: | J.D. Peak, University of Tennessee C.L. Melcher, University of Tennessee P.D. Rack, University of Tennessee |
| Correspondent: | Click to Email |
Positron Emission Tomography (PET) is a widely employed medical imaging technique that possesses the advantage of being able to image metabolic activity. In PET imaging a patient ingests a radioactive tracer and gamma rays resulting from positron annihilation are detected by a circular array of single crystal scintillators coupled to photomultiplier tubes (PMT). Since the scintillator crystals are the first step in PET detection, their performance is of paramount importance in final image quality and resolution. Large scintillator crystals are often grown via time consuming processes such as the Czochralski and Bridgman crystal growth techniques. The search for new scintillator crystals can be limited by the time consuming nature of the crystal growth. In this work, we will illustrate the use of a combinatorial thin film synthesis process that is being used to explore new scintillator materials. The combinatorial synthesis process utilizes three individual rf magnetron sputtering sources which can be simultaneously powered to generate a wide composition space of binary or ternary systems. In this work, we have investigated cerium doped lutetium oxyorthosilicate (LSO) as it is currently the most widely used scintillator crystal in PET imaging and provides a good benchmark for our proposed approach. LSO thin films with a gradient of cerium doping have been deposited to investigate the effects of cerium concentration and to compare the thin film properties to those of bulk LSO crystals. We have found that the emission spectra of the thin film materials have similar characteristics compared to the bulk crystals, and the emission intensity changes with the cerium concentration. Cerium doped lutetium-silicon oxide gradients have also been grown. X-ray diffraction measurements have been correlated to the equilibrium phase diagram, and the intensity of the luminescence emission spectra have been correlated with the corresponding phases of the lutetium-silicon system. In this presentation, we will discuss the combinatorial thin film synthesis process, and will correlate the observed structural, morphological, and chemical properties of the thin films to the measured optical properties.