Growth of high-quality nanowire avalanche photodiodes with separate absorption and multiplication structure using chemical vapor deposition

Avalanche photodiodes (APDs) are critical for high-sensitivity light detection; however, their fabrication is often hindered by high costs and complex processes, whereas conventional nanowire APDs fail to meet the performance demands of contemporary commercial applications. This study employs chemical vapor deposition (CVD) with quartz substrates and tubes to fabricate nanowire APDs featuring a separate absorption and multiplication (SAM) structure. The synthesized nanowires, characterized using scanning electron microscopy (SEM), Raman spectroscopy, and photoluminescence (PL), exhibit smooth surfaces, minimal defects, and excellent crystal quality. The resulting single nanowire SAM-APD demonstrates superior optoelectronic performance, achieving a photo-to-dark current ratio of 3.9 × 10 3 and a responsivity of 1.5 × 10 4 A/W, highlighting its potential for high-performance optical detection. This work introduces a cost-effective fabrication method for high-quality nanowire APDs, laying a foundation for advancements in optoelectronic devices.