Picosecond Photoconductivity and Vibrational Mode Screening in Double Helix Tin Iodide Phosphorus

Tin iodide phosphorus (SnIP) is an interesting new semiconductor that is the world's first non-templated inorganic double helix. Here we report on the first ultrafast study of SnIP, where we use THz spectroscopy to measure the carrier mobility and probe the relaxation dynamics. Additionally, we observe a vibrational mode at 1.49 THz and show how carrier screening reduces the oscillator amplitude, which manifests as a reduction in differential signal with Lorentzian lineshape.