17971
Recent advances in molecular organic photovoltaics ( OPVs ) have shown 10 % power conversion efficiency ( PCE ) for single - junction cells , which put them in direct competition with PVs based on amorphous silicon .
 Chemical: silicon
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: silicon