Optics

Physics

Dielectric

Physical chemistry

Homojunction

Responsivity

Chemistry

Materials science

Polarization (electrochemistry)

Photodetector

Specific detectivity

Optoelectronics

Doping

Ferroelectricity

Nature Communications

With the further miniaturization and integration of multi-dimensional optical information detection devices, polarization-sensitive photodetectors based on anisotropic low-dimension materials have attractive potential applications. However, the performance of these devices is restricted by intrinsic property of materials leading to a small polarization ratio of the detectors. Here, we construct a black phosphorus (BP) homojunction photodetector defined by ferroelectric domains with ultra-sensitive polarization photoresponse. With the modulation of ferroelectric field, the BP exhibits anisotropic dispersion changes, leading an increased photothermalelectric (PTE) current in the armchair (AC) direction. Moreover, the PN junction can promote the PTE current and accelerate carrier separation. As a result, the BP photodetector demonstrates an ultrahigh polarization ratio (PR) of 288 at 1450 nm incident light, a large photoresponsivity of 1.06 A/W, and a high detectivity of 1.27 × 10 11 cmHz 1/2 W −1 at room temperature. This work reveals the great potential of BP in future polarized light detection.

Ultra-sensitive polarization-resolved black phosphorus homojunction photodetector defined by ferroelectric domains