Breakthrough in Short-Wavelength Infrared Quantum Efficiency in Te-Hyperdoped Silicon Photodetectors via Light-Trapping Strategies.

We report a Si-CMOS-compatible photodiode for room temperature short-wavelength infrared detection. The architecture integrates Te-hyperdoped silicon with light-trapping structures to achieve a breakthrough in sub-band-gap efficiency. Specifically, by combining surface texturing and a back reflector, we boost absorptance to ≈85%, enabling the observation of transport dynamics at room temperature that were previously obscured in planar devices. We report a peak external quantum efficiency of 2.3% at 1.27  μm, exceeding commercial Si-PIN performance by 3 orders of magnitude. The physical origin of this enhancement is attributed to bias-assisted tunneling between the Te impurity band and the Si valence band, evidenced by a distinct spectral shoulder at 0.4-0.6 eV. Our results, supported by a specific detectivity of 4×10^{10}  cmHz^{1/2} W^{-1} and 32  μs response times, establish hyperdoped silicon as a viable platform for high-performance, room temperature SWIR photonics.