Bulk photovoltaic effect (BPVE), as a polarity-related unbiased light response, is expected to exceed the Shockley-Queisser limit in current optoelectronic devices, but the production of BPVE is usually limited to symmetry-breaking structural materials, such as ferroelectric materials Etc. usually have the disadvantage of low efficiency.

 In view of this, the National University of Singapore Chengkuo Lee, Cheng-Wei Qiu, etc. reported a metasurface graphene photodetector, which demonstrated the cascade polarization-sensitive light response under uniform illumination conditions, and constructed an artificial body photovoltaic effect BPVE.

Through non-centrosymmetric metal nano-antennas, the thermal photocarriers in graphene generate momentum during photoexcitation, forming a non-local directional shift current.
The response of the constructed unbiased and uncooled mid-infrared photodetector is three orders of magnitude higher than that of the traditional BPVE, and the noise power is only 0.12 nW Hz-1/2.

The vector light response is realized in the photo-responsive device, so that the polarization angle of light can be characterized by the same device. This method of constructing a device provides the possibility and experience for building a large-scale, affordable, and multifunctional infrared photodetector. , May be used for spatial optical communication, polarization imaging, plasmon enhanced molecular detection, etc.

References Wei, J., Li, Y., Wang, L. et al. Zero-bias mid-infrared graphene photodetectors with bulk photoresponse and calibration-free polarization detection. Nat Commun 11, 6404 (2020).DOI: 10.1038/ s41467-020-20115-1https://www.nature.com/articles/s41467-020-20115-1

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