The Modulation of Photoluminscences Band Gap of Two-Dimensional InSe Nanosheets on h-BN Substrate

Wafer-Scale Synthesis of High-Quality Semiconducting Two-Dimensional Layered InSe with Broadband Photoresponse

“…The strong reduction of PL intensity with decreasing thickness is also observable. All of these band gap values and PL intensity variation trends are consistent with that of previous works on InSe flakes isolated by scotch tape. − This PL behavior can be explained by the quantum confinement effect. With energy bands splitting into N -sub-bands for N -layer InSe nanosheets, the energy gap between the conduction and valence bands near the Γ-point is reduced, and then the optical band gap of multilayer InSe decreases accordingly.…”

“…The positions of the peaks measured from these films are independent of the film thickness, implying that the InSe layers are unstrained even if largely mismatching. 37 The similar results obtained from mechanical exfoliated InSe have previously been reported by others. 29,38 To further investigate the optical properties of PLD grown InSe, we employed photoluminescence (PL) spectroscopy to analyze the films with different thicknesses.…”

“…As shown in Figure b, Raman spectra were obtained from four different thick InSe films grown on SiO 2 /Si substrates. The positions of the peaks measured from these films are independent of the film thickness, implying that the InSe layers are unstrained even if largely mismatching . The similar results obtained from mechanical exfoliated InSe have previously been reported by others. , …”

A Dual-Band Multilayer InSe Self-Powered Photodetector with High Performance Induced by Surface Plasmon Resonance and Asymmetric Schottky Junction

“…17,18 In addition, a direct band gap (E g = 1.26 eV) at room temperature, which can increase up to 1.42 eV when its thickness is down to ∼6 nm, reveals a large spread of band gaps in the NIR region. 19 Nevertheless, most of present InSe-based photodetectors can only operate with a high responsivity in the short wavelength region, limiting their ability of photodetection in visible or NIR region. 16,20 Fortunately, with the ability to route and manipulate light at nanoscale beyond the diffraction limit, plasmonic technique offers opportunities to improve the quantum efficiency of photodetectors with high wavelength selectivity.…”

“…With the rapid developments in material science, some convenient methods such as mechanical exfoliation and chemical vapor deposition, etc ., have been developed to fabricate ultrathin 2D semiconductor materials with low cost. − However, it is difficult for a two-dimensional (2D) semiconductor material to build a multiband photodetector with high detectivity by taking its natural advantages. As an excellent rising star of 2D III–VI compounds semiconductor, InSe has a smaller electron effective mass ( m * = 0.143 m 0 ) compared with MoS 2 ( m * = 0.45 m 0 ), and the electronic devices based on InSe few-layers exhibit high mobility over 10 3 cm 2 V –1 s –1 at room temperature. , In addition, a direct band gap ( E g = 1.26 eV) at room temperature, which can increase up to 1.42 eV when its thickness is down to ∼6 nm, reveals a large spread of band gaps in the NIR region . Nevertheless, most of present InSe-based photodetectors can only operate with a high responsivity in the short wavelength region, limiting their ability of photodetection in visible or NIR region. , …”