Formation, stability and mobility of self-trapped excitations in NaI and NaI1-xTIx from first principles

Journal Article · Mon Mar 04 04:00:00 EST 2013 · Physical Review. B, Condensed Matter and Materials Physics, 87(11):Article No. 115101

DOI:https://doi.org/10.1103/PhysRevB.87.115101· OSTI ID:1068642

Prange, Micah P; Van Ginhoven, Renee M; Govind, Niranjan; Gao, Fei

We present ab initio calculations studying the formation, mobility, and stability of self trapped excitons (STE) and self trapped holes (STH) and electrons in NaI and NaI(Tl). While previously proposed models assumed a highly mobile STE and a slower STH, we find that both carriers in pure NaI have similar mobilities, with an activation energy of about 0.2 eV. We propose an alternate interpretation of experimental record including a new migration mechanism for the STE. In the Tl-doped material excitons preferentially trap at dopants, inducing off center distortions that have a structure unlike an STE providing a mechanism for light emission at multiple wavelengths. The calculated results are generally in excellent agreement with available data.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1068642
• Report Number(s): PNNL-SA-89847; 41094; NN2001000
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, 87(11):Article No. 115101, Journal Name: Physical Review. B, Condensed Matter and Materials Physics, 87(11):Article No. 115101
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory