Raw data for the plotted figures in my thesis are included. The thesis investigated quasi-2D perovskites and their applications of green light-emitting diodes. Data of the characterizations for perovskite materials (such as absorption, photoluminescence, scanning electron microscopy, X-ray diffraction, fourier-transform infrared spectroscopy etc.) and perovskite-based LEDs (device luminance, device efficiency, device stability etc.) are included.