Switchable magnetic bulk photovoltaic effect in the two dimensional magnet CrI3
The bulk photovoltaic effect (BPVE) rectifies light into the dc current in a single phase material and attracts the interest to design high efficiency solar cells beyond the pn junction paradigm. Because it is a hot electron effect, the BPVE surpasses the thermodynamic Shockley Queisser limit to generate above band gap photovoltage. While the guiding principle for BPVE materials is to break the crystal centrosymmetry, here we propose a magnetic photogalvanic effect (MPGE) that introduces the magnetism as a key ingredient and induces a giant BPVE. The MPGE emerges from the magnetism induced asymmetry of the carrier velocity in the band structure. We demonstrate the MPGE in a layered magnetic insulator CrI3, with much larger photoconductivity than any previously reported results. The photocurrent can be reversed and switched by controllable magnetic transitions. Our work paves a pathway to search for magnetic photovoltaic materials and to design switchable devices combining magnetic, electronic, and optical functionalities. Two dimensional (2D) material with intriguing physical properties promises advanced electronic and spintronic technologies. Here the authors predict a magnetic photo galvanic effect (MPGE) in bilayer 2D CrI3 due to the magnetism induced asymmetry of the carrier velocity in the band structure topology.
Nature Communications