The electrical transport properties of two-dimensional (2D) boron-doped 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 × 1013 cm−2. 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 10−2–10−1 cm2 V−1 s−1 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.