26804
The phase inversion is due to the positive - to - negative polarity switch in the current direction of the trapped charges at the current - biased graphene / SiO2 interface .
 Chemical: graphene; Chemical: SiO2
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: graphene; Chemical: SiO2