Synthesis of high resistive two-dimensional nonlayered Cr2S3 nanoflakes with stable phosphorus dopants by chemical vapor deposition

Heteroatom doping and surface passivation for the nonlayered two-dimensional materials could tune their band structures for the application of electronic and optoelectronic devices. Herein, we report the exploration for a stable synthesis strategy of phosphorous doping in the nonlayered Cr₂S₃ nanoflakes via chemical vapor deposition. Single crystalline ultrathin P-doped Cr₂S₃ nanoflakes were achieved by tuning the hydrogen gas and sample-source distance, reaching a lateral size of 10-50 μm and a thickness down to 4 nm. The elemental characterization was confirmed with surface P-S and P-O bonds and bulk P-Cr bonds, indicating the surface passivation and lattice incorporation of P atoms. More importantly, the electrical resistivity of P-doped Cr₂S₃ nanoflakes was demonstrated to be 10⁴ times compared to that of intrinsic Cr₂S₃, which could be explained by the liftup of Fermi level and surface passivation. Our work highlights phosphorous doping nonlayered Cr₂S₃ as tuning the electronic structure for achieving more intrinsic resistive samples. The heteroatom doping and surface passivation introduce a rational route for realizing the controllable electronic properties and provide more application potentials in the 2D electronic devices.