The Enhancement Of The APD For Blu-ray Detection In VLC

With the rapid development of visible light communication,the bottleneck problem of silicon Avalanche photodiode's low responsivity in blue light wave band greatly limits the development of the visible light communication.To obtain the high blue band responsivity APD device,we design and optimize a kind of the Separate Absorption-Charge-Multiplication structure APD based on the traditional APD structure in this paper.With support of the new type SACM APD model structure,we deduce the device internal electric field and dosage concentration in order to realize a bigger gain.To achieve frequency selection in blue band,we optimize the system of the device surface coating.Using the Silvaco software,technological process of APD device is simulated,as well as the thickness of absorption area and the doping concentration of multiplication area are optimized.The device's responsivity is 110A/W at 400 nm which is under the breakdown voltage of 70 V.It provides a reference to the manufacture of the device.