Tuning the Carrier Lifetime in Black Phosphorene through Family Atom Doping

It is highly desirable to control the carrier lifetime in two-dimensional (2D) materials to suit the needs of various device functionalities. In this work, by ab initio nonadiabatic molecular dynamics simulation, we find the single atom doping from phosphorus family elements can sufficiently tune the carrier lifetime in black phosphorene (BP). Instead of forming electron-hole (e-h) recombination centers, the e-h recombination is suppressed by doping compared with the pristine BP. Moreover, it is found the carrier lifetime has a strong correlation with the mass of the doping atoms. A doping atom with larger mass leads to a longer lifetime. With the heaviest family element Bi doping, the carrier lifetime increases from 0.29 to 5.34 ns. This trend can be understood from the reduction of the nuclear velocity due to the heavy doping atom. We propose this conclusion can be extended to other monoelemental 2D semiconductors, which provides important guidance for the future design of functional nanodevices.