Optical and morphological characterization of erbium phthalocyanine thin films on unpolished/polished substrates for enhanced solar water heating efficiency

In the present investigation, erbium phthalocyanine thin films are fabricated using the spray pyrolysis ultrasonic method for 20.0 min. The erbium phthalocyanine thin films are deposited on polished glass, silicon, aluminum, and stainless steel as substrates at a temperature of 70.0 °C and atmospheric pressure. Scanning electron microscopy images exhibited the characteristic nanosphere and nano-wires morphology associated with erbium phthalocyanine. Ultraviolet–visible spectroscopy displayed the Soret and Q bands of the erbium phthalocyanine thin films in a range of wavelength values of 339.0–391.0 nm and 550.0 to 750.0 nm, respectively, revealing slight variations in the absorption percentage attributed to the substrate polishing treatments. These findings demonstrate the suitability of erbium phthalocyanine thin films as absorbent materials in integrated solar water heaters and organic solar cell designs.