Demonstration of 4H-SiC UV single photon counting avalanche photodiode - Electronics Letters

Introduction: Single photon counting detectors enable the receiver of an optoelectronic system to achieve the ultimate receiver sensitivity, the quantum limit. They are also essential in applications that rely on the quantum nature of the light, such as quantum cryptography and quantum computing. Photomultiplier tubes (PMTs) are commonly used for single photon counting because of its high gain and relatively low dark count rate. Semiconductor silicon and InGaAs=InP single photon avalanche diodes (SPADs) have also been developed and widely used as photon counters with major advantages in size, weight, power and lifetime [1]. The spectral response of these solidstate photodetectors extends from 350 nm to near infrared, but is still poor in the UV range owing to the bandgap limitation. Recent progress in the wide-bandgap semiconductor such as SiC and GaN has resulted in the fabrication of UV detectors with high quantum efficiency and low leakage current such as the SiC avalanche photodiodes with extremely high gain ( 10) and low dark current [2]. In this Letter, we present the demonstration of the first SiC SPAD.