AlGaN solar-blind avalanche photodiodes with AlInN/AlGaN distributed Bragg reflectors.

AlGaN solar-blind avalanche photodiodes (APDs) with AlInN/AlGaN distributed Bragg reflectors (DBRs) operated at lower avalanche breakdown voltage are numerically demonstrated. The p-type AlGaN layer and the multiplicative layer with low Al composition are introduced to construct the polarization-induced electric field, which can significantly reduce the avalanche breakdown voltage of the APDs. Calculated results exhibit that the avalanche breakdown voltage of the designed APDs decrease by 13% compared with the conventional device structure. Simultaneously, an improved solar-blind spectral responsivity is achieved due to the inserted AlInN/AlGaN DBRs. [ABSTRACT FROM AUTHOR]