Environmentally friendly tin (Sn) perovskites have garnered significant attention for their potential to replace toxic lead-based counterparts in applications such as photovoltaics and light-emitting diodes (LEDs). Despite this promise, the performance of tin perovskite devices lags behind that of lead perovskites, with reported external quantum efficiencies of near-infrared Sn perovskite LEDs remaining below 10%. This limitation is primarily attributed to the presence of numerous defects within Sn perovskite crystallites and grain boundaries, leading to significant non-radiative recombination. While various epitaxy methods have been developed to obtain high-quality perovskites, their complex processes hinder the scalable fabrication of functional devices. In this study, we demonstrate the fabrication of epitaxial heterodimensional Sn perovskite films using a spin-coating process, enabling the realization of efficient LEDs with an external quantum efficiency of 11.6%. These films consist of a two-dimensional perovskite layer and a three-dimensional perovskite layer, exhibiting high order and a well-defined interface with minimal interfacial areas between the different dimensional perovskites. This unique nanostructure is achieved through the direct spin coating of a perovskite precursor solution containing tryptophan and SnF2 additives onto indium tin oxide glass. Our findings suggest that this approach holds potential for advancing the development of high-performance optoelectronic devices based on heterodimensional perovskites.