8471
OPVs incorporating these rr - P3HT / s - SWNT networks as the HTL demonstrate the best large area ( 70 mm ( 2 ) ) carbon nanotube incorporated organic solar cells to date with a power conversion efficiency of 7 . 6 % .
 P3HT, carbon
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 P3HT, carbon