The Tg distribution of 1944 molecules and Td distribution of 1182 OLED molecules are shown in Fig. . The Tg values span a range from 273 to 600 K, with the majority of values between 325 and 475 K. Fig. shows that compounds with a Tg higher than 400 K (127 °C) account for almost half of the reported compounds. The Td values span a range from 400 to 900 K, with the majority of values between 550 and 800 K. This indicates that the Td of most OLED materials is greater than 550 K (277 °C). The molecular structures include the atomic elements C, H, B, N, O, F, Si, P, S, Cl, and Br, containing most of the elements of pure organic functional materials.