Grating Perovskite Enhanced Polarization-Sensitive GaAs-Based Photodetector

In this work, we demonstrate the fabrication of GaAs photodetector with grating perovskite (G-PVK) for a broadband enhanced ultraviolet (UV)-near-infrared (NIR) photodetection. The device shows a peak photoresponse under 530-nm illumination, presenting a responsivity of 0.3 A/W, a specific detectivity of $2.24\,\,\times10$ ¹⁰ Jones, and 0.6/0.56 ms for rise/fall time, respectively. Compared to the device without PVK, the dark current was suppressed by two orders of magnitude and the photoresponse was enhanced up to 215%. This should be ascribed to the effective spatial separation of the vertical build-in electric field between GaAs and G-PVK and the enhanced light trapping arising from the diffraction grating. The well-aligned grating also shows a high sensitivity to the polarized light, giving rise to a peak-to-valley ratio ${I}_{{\mathrm {max}}} / {I}_{{\mathrm {min}}}$ of about 2.14. This suggests the potential application of the device in the polarization-sensitive imaging system.