Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: HL Poster I

HL 12.55: Poster

Montag, 1. April 2019, 17:30–20:00, Poster E

PbWO4 ground- and excited-state properties from first-principles calculations — •Johannes Bilk, Kris Holtgrewe, Christof Dues, and Simone Sanna — Justus-Liebig-Universität Gießen, Institut für theoretische Physik, Heinrich-Buff-Ring 16, 35392 Gießen

The scheelite tungstate crystals such as PbWO4 feature peculiar optical properties, including the excitonic luminescence, which is based on the radiative transition within tetrahedral (WO4)2- group, where the exciton becomes autolocalised. In particular, lead tungstate is a dense, fast scintillator material, which is often employed in high end calorimetric detectors in high energy physics accelerators [1]. Unfortunately, our theoretical knowledge of the models is still poor if compared to its technological relevance. In order to fill this gap, we present a comprehensive theoretical investigation of the scheelite phase of PbWO4. The atomic and electronic structure as well as the optical absorption are calculated for from first principles. The structural and optical properties predicted from local and hybrid density functional theory are in good agreement with experiment and earlier theoretical work [2]. The electronic structure and optical response are found to be very sensitive to the computational approach. Exact-exchange calculations are found to open the band gap substantially by 1.07 eV. In contrast to earlier calculations, good agreement with the measured optical data is achieved.

[1] M. Nikl et al., J. Appl. Phys. 91, 5041 (2002). [2] Y. Zhang et al., Phys. Rev. B 57, 12738 (1998).