Engineering the gain and bandwidth in avalanche photodetectors

• DOI: 10.1364/oe.446507
• Publication Date: 2022-04-22T14:00:08Z
• Authors: Cesar Bartolo-Perez; Ahasan Ahamed; Ahmed S. Mayet; Amita Rawat; Lisa McPhillips; Soroush Ghandiparsi; Julien Bec; Gerard Ariño-Estrada; Simon Cherry; Shih-Yuan Wang; Laura Marcu; M. Saif Islam
• Keywords: APDS; Avalanche diode

Avalanche and Single-Photon photodetectors (APDs SPADs) rely on the probability of photogenerated carriers to trigger a multiplication process. Photon penetration depth plays vital role in this In silicon APDs, significant fraction short visible wavelengths is absorbed close device surface that typically highly doped serve as contact. Most region can be lost by recombination, get slowly transported diffusion, or multiplied with high excess noise. On other hand, extended near-infrared requires thick semiconductors for efficient absorption. This diminishes speed devices due long transit time absorption layer required detecting most these photons. Here, we demonstrate it possible drive photons critical semiconductor film maximize their gain-bandwidth performance increase efficiency. approach engineering different enabled integrating photon-trapping nanoholes surface. The such 450 nm increased from 0.25 µm more than 0.62 µm. long-wavelength like 850 nm, reduced 18.3 only 2.3 µm, decreasing considerably. Such capabilities allow increasing gain APDs almost 400× at 9× nm. would enable designs requiring higher emerging technologies Fluorescence Lifetime Microscopy (FLIM), Time-of-Flight Positron Emission Tomography (TOF-PET), quantum communications systems, 3D imaging systems.