Impact of Molybdenum Dichalcogenides on the Active and Hole‐Transport Layers for Perovskite Solar Cells, X‐Ray Detectors, and Photodetectors

Abstract

The interface architectures of inorganic–organic halide perovskite‐based devices play key roles in achieving high performances with these devices. Indeed, the perovskite layer is essential for synergistic interactions with the other practical modules of these devices, such as the hole‐/electron‐transfer layers. In this work, a heterostructure geometry comprising transition‐metal dichalcogenides (TMDs) of molybdenum dichalcogenides (MoX2 = MoS2, MoSe2, and MoTe2) and perovskite‐ or hole‐transfer layers is prepared to achieve improved device characteristics of perovskite solar cells (PSCs), X‐ray detectors, and photodetectors. A superior efficiency of 11.36% is realized for the active layer with MoTe2 in the PSC device. Moreover, X‐ray detectors using modulated MoTe2 nanostructures in the active layers achieve 296 nA cm−2, 3.12 mA (Gy cm2)−1 and 3.32 × 10–4 cm2 V−1 s−1 of collected current density, sensitivity, and mobility, respectively. The fabricated photodetector produces a high photoresponsivity of 956 mA W−1 for a visible light source, with an excellent external quantum efficiency of 160% for the perovskite layer containing MoSe2 nanostructures. Density functional theory calculations are made for pure and MoX2 doped perovskites’ geometrical, density of states and optical properties variations evidently. Thus, the present study paves the way for using perovskite‐based devices modified by TMDs to develop highly efficient semiconductor devices.

Fabrication of High-Performance Solar Cells and X-ray Detectors Using MoX2@CNT Nanocomposite-Tuned Perovskite Layers

“…The calculated energy band structures for MAPbI 3 -CNT and MAPbI 3 -MoX 2 @CNT (X = S, Se, and Te) are presented in Figure e–h with a continuous energy range of −2.0 to 2.0 eV. The previously reported energy band gaps for MAPbI 3 , MAPbI 3 -MoS 2 , MAPbI 3 -MoSe 2 , and MAPbI 3 -MoTe 2 are 2.05, 0.4, 0.2, and 0.0 eV, respectively . From the calculated energy band structures, it is concluded that the addition of CNT with the TMD compounds (MAPbI 3 -CNT and MAPbI 3 -MoX 2 @CNT (X = S, Se, and Te)) establishes the metallic behavior (material with 0 eV band gap) as the valence band maxima (VBM) and conduction band minima (CBM) are overlapped with each other.…”

“…Figure a shows the Mo 3d high-resolution region for the MoS 2 @CNT hybrid which shows the 2H and 1T phase peaks related to 3d 3/2 and 3d 5/2 valence levels alongside the pathetic S 2s peak . The S 2p region reveals the divalent bands positioned at ∼162.3 and ∼161.8 eV, agreeing to 2p 1/2 and 2p 3/2 , respectively, for the MoS 2 @CNT nanocomposites (Figure b) . Further, the C 1s region from the CNT (Figure c) exposes a sharp peak at 283.7 related to the sp 2 carbon along with the Mo–C, O–C, and OC bands …”

“…Hence, indications cannot be transferred as monochromatic light but can be transmitted as wave packets. Eq can be used to express the wave packet group velocity in the dispersive medium …”

“…Hanwha Nanotech provided high-quality commercial carbon nanotubes (multiwalled CNTs, CM-95). The MoX 2 (MoS 2 , MoSe 2 , and MoTe 2 ) nanoparticle synthesis was done by following the previous literature . The MoX 2 @CNT hybrid nanostructures were prepared by mixing MoX 2 nanoparticles and CNTs in 50 mL of ethanol at a 1:1 weight ratio.…”

“…Recently, our group has explored the impact of MoX 2 (X = Se, S, and Te) TMD-doped perovskite-based devices for PSCs and photodetectors . The observed outcomes have clearly plotted the influence of MoX 2 doping to improve the device characteristics.…”