Design analysis of back-illuminated separated absorption and multiplication AlGaN APDs with polarization field
The p-type Al\(_\mathrm{x}\)Ga\(_{1-\mathrm{x}}\)N layer with different low Al-content is designed to utilize the polarization field to investigate the performance of back-illuminated separated absorption and multiplication AlGaN avalanche photodiodes. The results show that the avalanche breakdown voltage decreases and the multiplication gain increased as the Al content in the p-type layer decreases, which is due to the polarization field has the same direction as reverse bias field in the multiplication region. Moreover, the effects of both hole doping concentration in the p-Al\(_\mathrm{x}\)Ga\(_{1-\mathrm{x}}\)N layer and electron doping concentration in the inserted n-AlGaN layer on the performance of the designed APDs are studied in detail. It is demonstrated that the two parameters play important role on the devices properties.
polarization field p-type al\(_\mathrm{x}\)ga\(_{1-\mathrm{x}}\)n avalanche photodiodes