Abstract
We report nuclear magnetic resonance (NMR) measurements with in situ optical excitation of metastable defects in CdTe:In, CdTe:Ga, and CdF2:In. 113Cd nuclear spin–lattice relaxation rates (1/T1) in CdTe:In are about two orders of magnitude greater than in undoped CdTe, while relaxation rates in CdTe:Ga are indistinguishable from those in the undoped material. These results are consistent with the known doping properties of these impurities. Under illumination at 31K, a non-persistent, order-of-magnitude enhancement of the 113Cd relaxation rate is observed. After illumination, the rate is persistently enhanced by about 50%. The 113Cd relaxation rates in CdF2:In are strongly temperature-dependent as a result of interactions with thermally generated free carriers. This process is ineffective for 19F. The temperature dependence of the 113Cd rate yields an activation energy ΔE=185±10meV. Below 77K, the value of 1/T1 becomes independent of temperature. Under illumination, this rate is enhanced persistently by about a factor of two. These effects can be explained in terms of the “negative-U” DX model of bistability in these materials.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
