Journal of Modern Physics, 2017, 8, 770-785 http://www.scirp.org/journal/jmp ISSN Online: 2153-120X ISSN Print: 2153-1196 DOI: 10.4236/jmp.2017.85049 April 25, 2017 Nitrogen Desorption and Positron Sensitive Defect of CVD Diamond Kasey R. Lund 1 , Kelvin G. Lynn 2 , Marc H. Weber 3 , Chao Liu 4 , Elgin Eissler 4 1 National Superconducting Cyclotron Laboratory Michigan State University, East Lansing, MI, USA 2 Center for Materials Research, Department of Physics, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, USA 3 Center for Materials Research, Washington State University, Pullman, WA, USA 4 II-VI Incorporated, Saxonburg, PA, USA Abstract The chemical vapor deposition (CVD) process can produce single or poly- crystalline diamond samples of high purity or with controlled doping concen- trations. The defect type in the CVD diamonds can be changed by heating the samples. Controlling the defect type can be used to create devices for quantum diamond switches that could be used in radiation sensors and quantum in- formation technology. Eight samples of CVD diamonds were analyzed with Doppler broadening of positron annihilation radiation (DBAR) before and after annealing in high vacuum with an electron gun. Between temperatures of 1700 - 1850 K, nitrogen was liberated from the diamond sample. At these high temperatures, the surface was graphitized and a change in the color and transparency of the diamond was observed. Some of the samples were ana- lyzed with DBAR during periods with and without light. The defect properties were observed to change depending on the time exposure to the positron beam and were then regenerated by exposure to light. The DBAR data is compared to photoluminescence data and a time varying defect state is dis- cussed for detector and optical grade type II CVD diamonds. Keywords CVD Diamond Detectors, Positron Annihilation Spectroscopy, Divacancy 1. Introduction Much attention has been giving to CVD diamonds because of their electrical and mechanical properties. Previous work [1] [2] [3] has shown that CVD diamonds can be manipulated to tune their properties in order to create devices for quan- tum mechanical diamond switches that could be used in diamond sensors, io- How to cite this paper: Lund, K.R., Lynn, K.G., Weber, M.H., Liu, C. and Eissler, E. (2017) Nitrogen Desorption and Positron Sensitive Defect of CVD Diamond. Journal of Modern Physics, 8, 770-785. https://doi.org/10.4236/jmp.2017.85049 Received: March 9, 2017 Accepted: April 22, 2017 Published: April 25, 2017 Copyright © 2017 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access