Grating Perovskite Enhanced Polarization-Sensitive GaAs-Based Photodetector
Chunyan Wu, Bin Zeng, Kunnan Zhou, Longqiang Shan, Junjie Wang, Li Wang, Yizhong Yang, Yuxue Zhou, Lin‐Bao Luo
Abstract
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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.24\,\,\times10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{{\mathrm {max}}} / {I}_{{\mathrm {min}}}$ </tex-math></inline-formula> of about 2.14. This suggests the potential application of the device in the polarization-sensitive imaging system.