Perovskite materials have interesting optoelectronic properties such as tunable bandgap, high photoluminescence, broad spectral range, and emission tunability in the entire visible region. These materials have been extensively used as an absorber layer in the solar cells however their applications in terms of electrochemiluminescence (ECL) in the lighting industry has not been explored. This dissertation presents a study of the electrochemiluminescence, stability, size-dependent, and luminescent properties of these materials. Chapter 1 of this dissertation provides extensive background and a broad review of current research progress made in the field of perovskite materials and their applications. Chapter 2 illustrates the operation principles of several selected electrochemistry and characterization techniques extensively applied in this doctoral research. The doctoral research work starts with the synthesis and photophysical studies of perovskite films in Chapter 3 to show their fluorescence emission and stability. Confocal fluorescence microscopy is used to study the red and green fluorescence from the perovskite films and the origin and relationship between both colors are described. The synthesized perovskite films are used as a device for light-emitting electrochemical cells (LECs) applications. Since the optoelectronics properties of perovskite materials are greatly dependent on their size and structure, a perovskite size and density gradient are developed on a conductive substrate upon a single potential application as shown in Chapter 4. Dark field scattering (DFS), fluorescence imaging, X-ray crystallography (XRD), and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry techniques demonstrate that the large-sized and low-density perovskite crystals are more stable than the smaller sized high-density perovskite crystals. Finally, spectroelectrochemistry and photophysics, stability of perovskite quantum dots are described in Chapter 5. The generated ECL of perovskite quantum dots studied by was stabilized by incorporated the perovskite quantum dots in polystyrene (PS) polymer matrix increasing the efficiency of ECL generation 2.5 folds. Challenges of this doctoral work and future perspectives are described in Chapter 6.