Luminescence Spectroscopy of Sn₂P₂S₆ Crystals

Abstract

The emission and excitation spectra of luminescence of a Sn₂P₂S₆ crystal were studied in detail within wide temperature (12–360 K) and spectral (260–1000 nm) regions. Illumination with monochromatic light with the wavelength shorter than about 710 nm at low temperatures enabled to observe broad-band photoluminescence in the red and near-infrared spectral regions. Analysis of the emission spectra revealed a superimposition of three overlapping bands of nearly Gaussian shape peaking near 1.75, 1.57, and 1.39 eV at 12 K. At steady-state excitation at 12 K, the changes of photoluminescence intensity were observed with time of crystal illumination. During subsequent heating of the crystal with a rate of 0.082 K/s weak thermoluminescence was observed within 15–130 K. The trap depths of 41 and 88 meV, corresponding to two pronounced glow peaks near 22 and 41 K, were determined by the “initial rise” method.

Keywords:

• Tin hypothiodiphosphate
• photoluminescence
• thermoluminescence
• charge carrier traps

Acknowledgments

This research was supported by the grant No. 202/02/D072 of the Grant Agency of the Czech Republic and by the RP project No. 210000022.