Dielectric oligonucleotide fragments enable ultralow threshold photomultiplication in infrared quantum dot photodetectors

초록

Colloidal quantum dot-based shortwave infrared photodetectors offer a low-cost, scalable platform for applications such as autonomous driving and night vision. However, high-gain operation typically demands large operating voltages (VOP) due to inefficient carrier multiplication processes. Here, we report a photomultiplication (PM) photodiode mediated by a deoxyribonucleic acid (DNA) nucleotide-based charge tunneling layer (CTL). Systematic modulation of the DNA-based CTL suppresses dark current and enables precise control of the tunneling onset. The shallow energy levels and high permittivity of the DNA-based CTL enable efficient charge accumulation and hole injection via Fowler-Nordheim tunneling, yielding PM at-0.14 f 0.05 V. The resulting device achieved a gain of 57.6 and a specific detectivity (D*) of 1.2 x 1013 Jones at-0.5 V and 1550 nm.

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