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.