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B Monolayer Silicon Monochalcogenides b The polarization electric field induced by the dipole moment in monolayer silicon monochalcogenides is suitable to separate photo-generated carriers swiftly. The 2D polar monolayer silicon monochalcogenides with the polarization electric field would be potential catalysts for photocatalytic water splitting. Polarization Electric Field in 2D Polar Monolayer Silicon Monochalcogenides SiX (X = S, Se) as Potential Photocatalysts for Water Splitting. [Extracted from the article]

The polarization electric field generated by the dipole moment can swiftly separate photogenerated carriers. Herein, the first‐principles calculations to study the structural, electronic, polarization electric field, optical, and photocatalytic properties of 2D polar monolayer silicon monochalcogenide SiX (X = S, Se) are studied. The polarization electric field induced by a noncentrosymmetric structure is a direction from the X (X = S, Se) atomic surface to the Si atomic surface. The polar monolayer SiS (SiSe) is an indirect semiconductor with a bandgap of 2.997 eV (2.903 eV). The absorption coefficients of the polar monolayer SiX (X = S, Se) reach the order of 105 cm−1, and the absorption onset can be extended to the visible light region. The band alignment of the 2D polar monolayer SiX (X = S, Se) is suitable for photocatalytic water splitting. The obtained results show that the 2D polar monolayer SiX (X = S, Se) with a polarization electric field is a potential catalyst for photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

A high‐efficiency photocatalyst is critical for water splitting by solar light. Herein, via first principles calculations, the 2D polarized GeS/MoSe2 van der Waals (vdW) heterostructure is proposed as an efficient water redox photocatalyst. The performance of GeS/MoSe2 heterostructure is better than isolated materials, as the properties of GeS monolayer and MoSe2 monolayer are complementary by forming vdW heterostructure. GeS/MoSe2 heterostructure possesses suitable bandgap, dipole‐induced internal electric field, and excellent solar absorption performance. The band alignments of GeS/MoSe2 heterostructure are suitable compared with the redox potential of water. It is feasible to tune the optoelectronic properties and enhance photocatalytic activity of GeS/MoSe2 heterostructure via strain engineering. Biaxial compressive strain range from −2% to −3% induces the direct bandgap characteristic in GeS/MoSe2 heterostructure. The results suggest that 2D polarized GeS/MoSe2 vdW heterostructure is a potential novel high‐efficiency photocatalyst for water splitting under a wide range of spectra from ultraviolet to near infrared. [ABSTRACT FROM AUTHOR]

With ultrahigh carrier mobility and large band gap, blue phosphorene (bP) is a promising photoelectronics surpassing black phosphorene and can be further improved by heterostacking. Herein, strain‐engineering of the electronic band gaps and light absorption of two van der Waals heterostructures bP/MoS2 and bP/MoSe2 via first‐principles calculations has been reported. Their electronic band structures are sensitive to in‐plane strains. It is interesting and beneficial that biaxial compressive strain range of −0.02 to −0.055 induces the direct band gap in bP/MoSe2. There are two critical strains for bP/MoS(Se)2 heterostructures, where the semiconductor–metal transition can be observed. The bP/MoS(Se)2 heterostructures exhibit strong visible–ultraviolet light absorption, which can be further enhanced via biaxial strain. Our results suggest that bP/MoS(Se)2 heterostructures have promising electronics and visible–ultraviolet optoelectronic applications. [ABSTRACT FROM AUTHOR]