Université de Fribourg

Ultrafast dynamics of the surface photovoltage in potassium-doped black phosphorus

Kremer, Geoffroy ; Rumo, Maxime ; Yue, Changming ; Pulkkinen, Aki ; Nicholson, Christopher W. ; Jaouen, Thomas ; Von Rohr, Fabian ; Werner, Philipp ; Monney, Claude

In: Physical Review B, 2021, vol. 104, no. 3, p. 035125

Black phosphorus is a quasi-two-dimensional layered semiconductor with a narrow direct band gap of 0.3 eV. A giant surface Stark effect can be produced by the potassium doping of black phosphorus, leading to a semiconductor to semimetal phase transition originating from the creation of a strong surface dipole and associated band bending. By using time- and angle-resolved photoemission ...