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

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 Egopt 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).