Silicon Carbide (SiC) Avalanche Photodiodes (APDs) are highly sensitive photodetectors that convert UV radiation into electrical signals with internal gain. Operating at high reverse bias close to the diode breakdown voltage (VBR), they exploit the avalanche multiplication effect: a single photon generates electron-hole pairs, which are accelerated in a strong electric field, creating further carriers through impact ionization. This results in a multiplication factor or internal gain M of up to several hundred, enabling detection of very weak radiation signals. In linear mode (reverse bias 3-5 V below VBR), the output current is proportional to the incident UV irradiance, providing precise measurements with high dynamic range and good linearity.
Typical applications include fire and flame detection or radiation monitoring. In Geiger mode (reverse bias just below (VBR), SiC APDs act as single-photon avalanche diodes (SPADs), generating one digital pulse per detected photon. This enables single-photon counting for ultra-low irradiance applications such as fluorescence detection, time-correlated single-photon counting (TCSPC), and quantum optics. SiC APDs offer superior UV sensitivity, low breakdown voltage, low noise, visible blindness and robustness under harsh environmental conditions.
| Type | SiC APD |
| Wavelength | UV Broadband |
| Maximum Responsivity | 100 A/W |
| Package | TO-5 |
| Active area |
0.2 mm2 |
| Operating temperature | -55 to 170 C |
