Solar photovoltaic energy is a clean and renewable source of electricity that has been researched heavily over the past 30 years. However, cost, toxicity, and rarity of precursor elements still limit widespread implementation of current technologies. Solution processing of these materials, such as hydrothermal synthesis, is desirable due to its low cost and scalability. Yet, these methods generally produce materials of lower electronic quality with defects and impurities that can limit carrier collection. Ferroelectrics may be able to withstand such drawbacks because of an internal electric field that can effectively separate carriers to reduce recombination rates. Antimony Sulfoiodide (SbSI) is a relatively unstudied ferroelectric with promising properties for solar cell absorber applications.
In this work, the semiconductor SbSI was synthesized hydrothermally to produce crystals that were 650 microns long and 30 microns in diameter on average. These microrods were synthesized from a published procedure, but had variances in pH and seeding, where a decrease in pH increased crystal size. Scanning electron microscopy (SEM) showed SbSI is highly crystalline, while X-ray diffraction (XRD) confirmed the phase purity. Diffuse reflectance measurements for Tauc plots estimated an indirect band gap of 1.85 eV. Current work on measuring the carrier lifetimes and mobilities via ultrafast terahertz spectroscopy will help evaluate further pursuit of SbSI as an absorber material.
In this work, the semiconductor SbSI was synthesized hydrothermally to produce crystals that were 650 microns long and 30 microns in diameter on average. These microrods were synthesized from a published procedure, but had variances in pH and seeding, where a decrease in pH increased crystal size. Scanning electron microscopy (SEM) showed SbSI is highly crystalline, while X-ray diffraction (XRD) confirmed the phase purity. Diffuse reflectance measurements for Tauc plots estimated an indirect band gap of 1.85 eV. Current work on measuring the carrier lifetimes and mobilities via ultrafast terahertz spectroscopy will help evaluate further pursuit of SbSI as an absorber material.