This study reports the synthesis of stable, nanometer-sized CH₃NH₃PbBr₃ perovskite nanoparticles using a simple and fast method. The nanoparticles, approximately 6 nm in size, are dispersible in a wide range of organic solvents and remain stable in both solid and concentrated solution forms for over three months without the need for mesoporous materials. This stability enables the preparation of homogeneous thin films via spin-coating on a quartz substrate. Both the colloidal solution and the thin film emit light within a narrow bandwidth of the visible spectrum with a high quantum yield (around 20%), which is advantageous for optoelectronic devices. Organolead halide perovskites, such as CH₃NH₃PbX₃, are hybrid materials combining the properties of organic and inorganic materials. These materials have shown great promise in photovoltaic applications due to their unique optical and excitonic properties, as well as their electrical conductivity. The study demonstrates the preparation of CH₃NH₃PbBr₃ nanoparticles using a medium-chain ammonium bromide as a capping agent, which allows for the formation of stable colloidal solutions. The nanoparticles were synthesized by reacting CH₃NH₃Br with PbBr₂ in the presence of oleic acid and octadecene. The resulting nanoparticles were highly crystalline and exhibited excellent optical properties. The study also shows that the use of shorter alkyl chain ammonium cations can be advantageous for future applications of these nanoparticles. The prepared nanoparticles were found to be highly stable under light illumination and could be dispersed in various organic solvents. X-ray powder diffraction analysis confirmed the phase purity and crystallinity of the nanoparticles, which were found to have a cubic structure with a lattice parameter of approximately 5.93 Å. The nanoparticles were used to prepare a homogeneous thin film on a quartz substrate, which exhibited a high quantum yield and a narrow emission band. A thin film light-emitting device based on these nanoparticles was also prepared, showing improved electroluminescence compared to a reference device based on a bulk film of the same material. The study concludes that the synthesis of CH₃NH₃PbBr₃ nanoparticles is feasible using a simple method, and these nanoparticles have potential applications in optoelectronic devices due to their stability, optical properties, and ease of preparation.This study reports the synthesis of stable, nanometer-sized CH₃NH₃PbBr₃ perovskite nanoparticles using a simple and fast method. The nanoparticles, approximately 6 nm in size, are dispersible in a wide range of organic solvents and remain stable in both solid and concentrated solution forms for over three months without the need for mesoporous materials. This stability enables the preparation of homogeneous thin films via spin-coating on a quartz substrate. Both the colloidal solution and the thin film emit light within a narrow bandwidth of the visible spectrum with a high quantum yield (around 20%), which is advantageous for optoelectronic devices. Organolead halide perovskites, such as CH₃NH₃PbX₃, are hybrid materials combining the properties of organic and inorganic materials. These materials have shown great promise in photovoltaic applications due to their unique optical and excitonic properties, as well as their electrical conductivity. The study demonstrates the preparation of CH₃NH₃PbBr₃ nanoparticles using a medium-chain ammonium bromide as a capping agent, which allows for the formation of stable colloidal solutions. The nanoparticles were synthesized by reacting CH₃NH₃Br with PbBr₂ in the presence of oleic acid and octadecene. The resulting nanoparticles were highly crystalline and exhibited excellent optical properties. The study also shows that the use of shorter alkyl chain ammonium cations can be advantageous for future applications of these nanoparticles. The prepared nanoparticles were found to be highly stable under light illumination and could be dispersed in various organic solvents. X-ray powder diffraction analysis confirmed the phase purity and crystallinity of the nanoparticles, which were found to have a cubic structure with a lattice parameter of approximately 5.93 Å. The nanoparticles were used to prepare a homogeneous thin film on a quartz substrate, which exhibited a high quantum yield and a narrow emission band. A thin film light-emitting device based on these nanoparticles was also prepared, showing improved electroluminescence compared to a reference device based on a bulk film of the same material. The study concludes that the synthesis of CH₃NH₃PbBr₃ nanoparticles is feasible using a simple method, and these nanoparticles have potential applications in optoelectronic devices due to their stability, optical properties, and ease of preparation.