A novel technique using air-gap transistor stamps enabled the observation of intrinsic charge transport on the surface of rubrene crystals over a wide temperature range. The intrinsic transport is characterized by anisotropic carrier mobility and an increase in mobility with cooling. At lower temperatures, where transport is dominated by shallow traps, mobility decreases exponentially with cooling and anisotropy vanishes. Deep traps, introduced by X-ray radiation, increase the field-effect threshold without affecting mobility. These traps do not scatter mobile polaronic carriers. The study addresses the challenge of demonstrating intrinsic charge transport in organic semiconductors, which is hindered by the polaronic nature of charge carriers and static disorder. Time-of-flight (TOF) experiments have been used as a benchmark, but recent advances in single-crystal organic field-effect transistors (OFETs) allow for the study of surface transport with reduced disorder. The air-gap transistor stamps enabled high room-temperature mobility for p-type carriers (~20 cm²/Vs). The mobility anisotropy and temperature dependence of mobility were observed in the temperature range 150-300 K. At lower temperatures, mobility decreases with cooling and anisotropy vanishes. The energy diagram near the HOMO level in rubrene shows localized states (traps) associated with crystal defects. Injection of p-type carriers fills these traps and shifts the Fermi level towards the HOMO. Below the field-effect threshold, charge is trapped in deep traps, while above the threshold, carriers are thermally excited from shallow traps to the HOMO level, increasing surface conductivity. The mobility anisotropy persists down to ~150 K, and the field-effect threshold increases with cooling. The mobility along the b-axis is higher than along the a-axis due to stronger π-π overlap. The temperature dependence of mobility is fitted by an activation dependence with an activation energy of ~70 meV. The study shows that at high temperatures, mobility is anisotropic and increases with cooling, while at lower temperatures, mobility decreases rapidly and anisotropy vanishes. The experiments also show that deep traps do not scatter mobile polarons. The results highlight the importance of trap states in organic semiconductors and the role of temperature in charge transport.A novel technique using air-gap transistor stamps enabled the observation of intrinsic charge transport on the surface of rubrene crystals over a wide temperature range. The intrinsic transport is characterized by anisotropic carrier mobility and an increase in mobility with cooling. At lower temperatures, where transport is dominated by shallow traps, mobility decreases exponentially with cooling and anisotropy vanishes. Deep traps, introduced by X-ray radiation, increase the field-effect threshold without affecting mobility. These traps do not scatter mobile polaronic carriers. The study addresses the challenge of demonstrating intrinsic charge transport in organic semiconductors, which is hindered by the polaronic nature of charge carriers and static disorder. Time-of-flight (TOF) experiments have been used as a benchmark, but recent advances in single-crystal organic field-effect transistors (OFETs) allow for the study of surface transport with reduced disorder. The air-gap transistor stamps enabled high room-temperature mobility for p-type carriers (~20 cm²/Vs). The mobility anisotropy and temperature dependence of mobility were observed in the temperature range 150-300 K. At lower temperatures, mobility decreases with cooling and anisotropy vanishes. The energy diagram near the HOMO level in rubrene shows localized states (traps) associated with crystal defects. Injection of p-type carriers fills these traps and shifts the Fermi level towards the HOMO. Below the field-effect threshold, charge is trapped in deep traps, while above the threshold, carriers are thermally excited from shallow traps to the HOMO level, increasing surface conductivity. The mobility anisotropy persists down to ~150 K, and the field-effect threshold increases with cooling. The mobility along the b-axis is higher than along the a-axis due to stronger π-π overlap. The temperature dependence of mobility is fitted by an activation dependence with an activation energy of ~70 meV. The study shows that at high temperatures, mobility is anisotropic and increases with cooling, while at lower temperatures, mobility decreases rapidly and anisotropy vanishes. The experiments also show that deep traps do not scatter mobile polarons. The results highlight the importance of trap states in organic semiconductors and the role of temperature in charge transport.