Work

2D Semiconductors Directly Grown on Si with Room Temperature Mobility Exceeding 2000 cm 2 V −1 s −1

Year: 2025

Type: article

Abstract: Bi 2 O 2 Se has recently attracted immense interest in nanoelectronics and optoelectronics for its superior mobility, ferroelectric order, tunable bandgap, and exceptional air stability. However, until now, the direct growth of Bi 2 O 2 Se is limited to mica, or perovskite oxide substrates [SrTiO 3 , LaAlO 3 , (La, Sr)(Al, Ta)O 3 ], incompatible with mainstream semiconductor processes, and the room temperature mobility is limited to ≈800 cm 2 V −1 s −1 . Here, the controllable growth of Bi 2 O 2 Se nanoflakes on SiO 2 /Si substrates is reported and with room temperature electron mobility higher than 2000 cm 2 V −1 s −1 , exceeding all previous reports. The unpreceded in‐plane electron mobility is found to strongly correlate with the out‐of‐plane ferroelectric order, which is stabilized by the expanded c‐lattice in oxygen‐deficient Bi 2 O 2 Se. The stabilized ferroelectric phase is confirmed by piezoresponse force microscopy (PFM) and anisotropic transport property measurements, which generally possess a high dielectric constant, thus reducing the impurity scattering. The silicon‐compatible ultrahigh mobility Bi 2 O 2 Se sheds light to high‐performance electronic devices.

Source: Small

DOI: 10.1002/smll.202500026