Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of C...Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of CsPbI_(3) and transition metal dichalcogenides(TMDCs),their heterostructure present potential applications in both photonics and optoelectronics fields.Here,we demonstrate selective growth of cubic phase CsPbI_(3) nanofilm with thickness as thin as 4.0 nm and Zigzag/armchair orientated nanowires(NWs)on monolayer WSe_(2).Furthermore,we show growth of CsPbI_(3) on both transferred WSe_(2) on copper grid and WSe_(2) based optoelectrical devices,providing a platform for structure analysis and device performance modification.Transmission electron microscopy(TEM)results reveal the epitaxial nature of cubic CsPbI_(3) phase.The revealed growth fundamental of CsPbI_(3) is universal valid for other twodimensional substrates,offering a great advantage to fabricate CsPbI_(3) based van der Waals heterostructures(vdWHs).X-ray photoelectron spectroscopy(XPS)and optical characterization confirm the type-II band alignment,resulting in a fast charger transfer process and the occurrence of a broad emission peak with lower energy.The formation of WSe_(2)/CsPbI_(3) heterostructure largely enhance the photocurrent from 2.38 nA to 38.59 nA.These findings are vital for bottom-up epitaxy of inorganic semiconductor on atomic thin 2D substrates for optoelectronic applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61974166 and 62274184)the Hunan Provincial Natural Science Foundation of China(Grant Nos.2021JJ20080 and 2021JJ20077)。
文摘Van der Waals epitaxy allows heterostructure formation without considering the lattice match requirement,thus is a promising method to form 2D/2D and 2D/3D heterojunction.Considering the unique optical properties of CsPbI_(3) and transition metal dichalcogenides(TMDCs),their heterostructure present potential applications in both photonics and optoelectronics fields.Here,we demonstrate selective growth of cubic phase CsPbI_(3) nanofilm with thickness as thin as 4.0 nm and Zigzag/armchair orientated nanowires(NWs)on monolayer WSe_(2).Furthermore,we show growth of CsPbI_(3) on both transferred WSe_(2) on copper grid and WSe_(2) based optoelectrical devices,providing a platform for structure analysis and device performance modification.Transmission electron microscopy(TEM)results reveal the epitaxial nature of cubic CsPbI_(3) phase.The revealed growth fundamental of CsPbI_(3) is universal valid for other twodimensional substrates,offering a great advantage to fabricate CsPbI_(3) based van der Waals heterostructures(vdWHs).X-ray photoelectron spectroscopy(XPS)and optical characterization confirm the type-II band alignment,resulting in a fast charger transfer process and the occurrence of a broad emission peak with lower energy.The formation of WSe_(2)/CsPbI_(3) heterostructure largely enhance the photocurrent from 2.38 nA to 38.59 nA.These findings are vital for bottom-up epitaxy of inorganic semiconductor on atomic thin 2D substrates for optoelectronic applications.
