Harnessing Non‐Centrosymmetry in GaSb for Giant Bulk Photovoltaics and Intelligent Near‐Infrared Perception

ABSTRACT Bulk photovoltaic effect (BPVE) enables self‐powered optoelectronics beyond the Shockley‐Queisser limit, yet high‐performance junction‐free near‐infrared (NIR) detectors remain elusive due to weak intrinsic non‐centrosymmetry and severe dark current in existing narrow‐gap semiconductors. Herein, we synthesize polar needle‐like GaSb single crystals via self‐catalyzed CVD, exploiting its 0.72 eV direct bandgap, uniform non‐centrosymmetric polarity, and high crystallinity to realize a zero‐bias GaSb field‐effect‐transistor (FET) architecture coupled with an ultra‐broad 210‐1800 nm photoresponse and ultralow ∼3 pA dark current. At 1550 nm and 100 mW/cm 2 , five devices deliver a mean short‐circuit current density of 17.9 ± 12.0 mA/cm 2 (increased up to 349.37 ± 191.75 mA/cm 2 upon 10 W/cm 2 illumination) and an effective bulk photovoltaic coefficient (β eff ) of 0.18 ± 0.12 V −1 . Near a tiny −4 mV transition bias, switchable bipolar photoresponse yields an exceptional polarization‐current ratio approaching 300. Mechanistic studies verify that intrinsic shift current dominates the channel photocurrent, modulated by photon‐drag injection and local Dember effect. Beyond photodetection, we integrate GaSb FET with response‐guided computational imaging and a lightweight convolutional neural network, boosting letter‐recognition accuracy through scattering media from 63.8% to 99.4%. This work establishes GaSb as a transformative BPVE platform, advancing low‐power polarization‐resolved NIR intelligent perception by integrating material symmetry engineering, device physics, and computational imaging.