Although 2D|3D has shown potential for application in multifunctional devices, the principle of operation for multifunction devices (SOLAR Cell-LED: SOLED) has not yet been revealed. However, most studies have reported that the devices have only one auspicious characteristic. Here in this study the SOLED devices are monitored and investigated in a 2D|3D heterostructure with a multidimensional perovskite. It is fond that a 2D|3D heterostructure with a multidimensional perovskite interface induces carrier transmission from the interface, increasing the density of electrons and holes, and increasing their recombination. An interface-engineered perovskite 2D|3D-heterojunction structure is employed to realize the multifunctional photonic device in on-chip, exhibiting overall power conversion efficiencies of photovoltaics up to 21.02% under AM1.5, and external quantum efficiency of the light-emitting diode up to 5.13%. This novel phenomenon is attributed to carrier transfer resulting in a high carrier density and enhanced carrier recombination at the 2D|3D interface.