The paper by Koenig et al. investigates the electric field effect in few-layer black phosphorus (BP) devices on Si/SiO$_2$. They demonstrate field-effect transistors using both four-probe and two-point configurations, measuring charge carrier mobility and drain current modulation. At room temperature, they achieve mobilities of up to 300 cm$^2$/Vs and drain current modulation exceeding 10$^3$. At lower temperatures, the on-off ratio exceeds 10$^5$, and the devices exhibit both electron and hole conduction. Atomic force microscopy reveals significant surface roughening of thin BP crystals within an hour after exfoliation, which may limit device performance. The study highlights the potential of BP as a promising material for next-generation two-dimensional electronic devices, despite the need for encapsulation to mitigate environmental degradation.The paper by Koenig et al. investigates the electric field effect in few-layer black phosphorus (BP) devices on Si/SiO$_2$. They demonstrate field-effect transistors using both four-probe and two-point configurations, measuring charge carrier mobility and drain current modulation. At room temperature, they achieve mobilities of up to 300 cm$^2$/Vs and drain current modulation exceeding 10$^3$. At lower temperatures, the on-off ratio exceeds 10$^5$, and the devices exhibit both electron and hole conduction. Atomic force microscopy reveals significant surface roughening of thin BP crystals within an hour after exfoliation, which may limit device performance. The study highlights the potential of BP as a promising material for next-generation two-dimensional electronic devices, despite the need for encapsulation to mitigate environmental degradation.