Enhanced domain wall conductivity in photosensitive ferroelectrics Sn2P2S6 with full-visible-spectrum absorption

Recent optical stimulation suggests a vital non-contact pathway to manipulate both macroscopic and microscopic ferroelectric properties paves the foundation for optoelectronics devices. However, up date, most optical-related manipulation of is restricted due their intrinsic bandgap limited visible light spectrum absorption. Here, we reveal non-oxide Sn2P2S6 single crystal possesses full-visible-spectrum absorption (from 300 800 nm) with unique disproportionation mechanism photoexcited Sn ions Urbach tail, which not contradicting band gap. Interestingly, observed existence conductive domain walls (c-DW) illumination induced significant enhancement wall conductivity caused by such reaction. In addition, domains separated c-DW also exhibited noticeable electrical difference in presence owing interfacial polarization charge opposite signs. The result provides novel opportunity understanding behavior ferroelectrics achieving greatly enhanced performances optoelectronics.