Low-temperature mobility-lifetime product in synthetic diamond

The mobility-lifetime ( μ τ) product is an important parameter that determines the performance of electronic and photonic devices. To overcome the previously reported difficulties in measuring the μ τ product at cryogenic temperatures, we implement a time-resolved cyclotron resonance method to determine the carrier lifetime τ. After clarifying the difference between the AC and DC mobilities measured by cyclotron resonance and time-of-flight methods, respectively, we demonstrate an inverse temperature dependence of the μ τ product. The highest recorded μ τ product of 0.2 cm2/V, which is approximately 100 times the room-temperature value, was obtained at 2 K for chemical-vapor-deposition diamond of the highest currently available purity.