Photon counting detector with picosecond timing resolution for X to visible range on the basis of GaP

Avalanche photodiodes specifically designed for single photon counting devices have been developed on the basis of various semiconductor materials: Si, Ge, GaP, GaAsP, and InGaAs at the Czech Technical University within the last 20 years. All the semiconductor detectors operate at a room temperature or at thermoelectrically achievable temperatures except of the germanium-based detector, which requires liquid nitrogen cooling. Electronic circuits for these detectors biasing, quenching and control have been developed and optimized for different applications. Timing resolution of solid-state photon counters as high as 50 ps full width at a half maximum has been achieved when detecting single photon signals. Circuits permitting operation of solid-state photon counters in both single and multiple photon signal regimes have been developed and applied. The compact and rugged design, radiation resistance, and low operating voltage are attractive features of solid state photon counters in various applications including the space projects. The sensitivity of solid-state photon counters spans from X-ray up to 1800 nm in the near infrared region. The avalanche structures based on the GaP material exhibit several special features for X-ray operation: the timing resolution as high 100 ps may be achieved when detecting individual quanta, the wavelength range spans from 0.1 nm up to visible light. The GaP exhibits from all the existing solid-state photon counters the highest detection efficiency in X-ray, it reaches 14% at 0.1 nm band.