The electrical transport properties of two-dimensional (2D) borondoped delta layers were investigated by a comprehensive analysis of physical, electrochemical and microscopic methods. The boron concentration profile was determined physically by elastic recoil detection (ERD) and compared to the doping (acceptor) profile extracted from capacitance-voltage (CV) measurements, giving a boron concentration of 2-4 Â 10 13 cm À2 . Corresponding field effect transistor (FET) characteristics, based on the boron-doped delta channel concept, measured in electrolyte, show good modulation behaviour but field effect mobilities in the range of 10 À2 -10 À1 cm 2 V À1 s À1 that are far below expected values. High-resolution transmission electron microscopy (HR-TEM) analysis was employed to shed new light on the transport behaviour of boron-doped delta layers, revealing an inhomogeneous and interrupted morphology. Based on this finding, a hypothesis is proposed, modelling the delta layer transport behaviour via hopping and tunnelling processes between boron clusters.