Reductant-free synthesis of Se micro/nanostructures with different morphologies from SeCl₄ via a simple hydrothermal approach and its photovoltaic application

Herein, three-dimensional selenium (Se) nanostructures were successfully synthesized via a simple hydrothermal route without using any reducing agent for the first time. SeCl₄ as Se source and CTAB as surfactant were employed. The as-synthesized products were extensively characterized by techniques such as X-ray diffraction, Energy dispersive spectrometry, Scanning electron microscopy, Transmission electron microscope, Fourier transform infrared spectroscopy and Diffused reflectance UV–visible spectrum. Our results showed that with using no reluctant in this hydrothermal condition, Se(IV) can be completely reduced to Se⁰. Effect of temperature, surfactant, time, solvent and pH on final products morphologies and particles size were investigated. The findings revealed that the noted parameters have great effect on morphology and quality of final products. To fabricate a FTO/TiO₂/Se/Pt-FTO solar cell, selenium film was directly deposited on top of the TiO₂ by Doctor’s blade method. Solar cell results indicate that an inexpensive solar cell could be developed by synthesis of Se nanoparticles through hydrothermal method.