Impact of substrate -target distance on the hemispherical expansion plume generated by the deposit of SnSe nanoparticle thin films
The PLD technique is used to develop SnSe thin films on quartz substrates using a Nd: YAG pulsed laser at a deposition temperature of (573 K) with varied substrate-target distances (2,2.5,3, and 3.5) cm. The produced thin films are characterized using XRD, which reveals an orthorhombic structure with a polycrystalline system. Using transmittance spectra to calculate the energy band gap, which ranges from (1.71-3.65) eV. Absorption coefficient, refractive index, loss factor (loss tangent), extinction coefficient, and optical conductivity are affected by substrate-target distance Ds-t) change. The dislocation density and particle size are changed by the Ds-t change, too. FESEM shows the film morphology and reveals the formation of two structures: a pop-corn like structure and nanorods.