Doping modification and optoelectronic properties of black phosphorus

Black phosphorus (BP) has attracted much attention for its excellent electrical and optical properties and its potential in field-effect transistors (FETs). In this work, BP doped with oxygen group elements (sulfur, selenium, and tellurium) was successfully synthesized using the chemical vapor transport method (CVT), and their optoelectronic properties were studied systematically. It is confirmed by X-ray diffraction (XRD) that BP crystals doped with the oxygen group elements exhibited high crystalline quality and yield. Changes in the absorption spectra and surface morphology indicated that doped BP demonstrated significantly enhanced environmental stability compared to undoped BP under prolonged air exposure. Among the doped samples, tellurium (Te)-doped BP showed the highest stability, with a degradation rate of only 9.91 % after 10 days. FETs based on doped BP were successfully fabricated, and their electrical performances were thoroughly evaluated. We found that the hole mobility of BP was dramatically improved by doping, and the selenium (Se)-doped BP possessed the highest hole mobility of 1684.24 cm 2 /V·s.