Thermal and optical properties of AgSbS2 thin films prepared by pulsed laser deposition (PLD)

Abstract Thin amorphous AgSbS2 films were deposited as the potential candidate for new phase-change memory material. Thin films were prepared by pulsed laser deposition (PLD) from AgSbS2 polycrystalline bulk samples. Bulk samples were prepared by melt-quench technique from pure elements. Composition and chemical homogeneity of these bulks were checked by scanning electron microscopy with energy dispersive analysis (SEM-EDX); the crystallinity was studied by X-ray diffraction (XRD). Prepared thin films were characterized by electron microprobe SEM-EDX (composition, chemical homogeneity, surface morphology), differential scanning calorimetry DSC (crystallization temperature Tc, phase transformation temperature TLT→HT and melting temperature Tm) and by UV–Vis–NIR spectroscopy (film thickness d, spectral dependence of refractive index n, single oscillator energy E0, dispersion energy Ed, and optical band gap energy E g opt values). The phase-change recording process in amorphous AgSbS2 thin films was tested via photocrystallization experiments done by Ar+ ion laser. The laser exposed dots were studied by scanning electron microscopy (SEM) and transmission optical microscopy. Micro X-ray diffraction (μ-XRD) was used for exposed dot crystallinity study. The kinetics of phase transition was traced by measurement of optical transmission in dependence on laser exposure time (photocrystallization kinetic curve).