16560
Since the discovery of electroluminescence in the phenyl - based conjugated polymers in 1990 , the field of polymer optoelectronics has matured to the extent that presently a wide class of devices have been commercialized .
 Chemical: phenyl
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: phenyl