9741
This article reviews the recent progress on ternary organic photovoltaic systems , including polymer / small molecule / functional fullerene , polymer / polymer / functional fullerene , small molecule / small molecule / functional fullerene , polymer / functional fullerene I / functional fullerene II , and polymer / quantum dot or metal / functional fullerene systems .
 Chemical: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene
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: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene; Chemical: fullerene