Hall mobility in tin iodide perovskite CH3NH3SnI3: Evidence for a doped semiconductor

• Hole concentration in highly conducting CH3NH3SnI3 was determined.
• Hall mobility was not affected by artificial hole doping.
• The electronic structure can be described as that of an intrinsic semiconductor.

CH3NH3SnI3 is a metal halide perovskite that shows metallic conductivity over a wide temperature range, although ab initio calculations and optical absorption indicate that its band structure is consistent with that of an intrinsic semiconductor. Hall effect measurements of as-grown crystals give a hole concentration of about 9×1017 cm−3 with rather high Hall mobility of about 200 cm2 V−1 s−1 at 250 K. Artificial hole doping enhances the electrical conductivity of the crystals without influencing mobility. These observations indicate that the electronic structure in stoichiometric CH3NH3SnI3 can be described as that of an intrinsic semiconductor with a wide valence band. This situation leads to metal-like conduction with even a trace amount of spontaneous hole doping in the as-grown crystal.

Hall effect measurements of as-grown CH3NH3SnI3 crystals give a hole concentration of about 9×1017 cm−3. Artificial hole doping enhances the electrical conductivity of the crystals without influencing mobility, indicating that the electronic structure of CH3NH3SnI3 can be described as that of an intrinsic semiconductor with a wide valence band.Figure optionsDownload as PowerPoint slide