17322
The internal transport and recombination parameters of solid - state dye - sensitized solar cells ( ssDSCs ) using the amorphous organic semiconductor 2 , 2 ' , 7 , 7 ' - tetrakis ( N , N - di - p - methoxyphenylamine ) - 9 , 9 ' - spirobifluorene ( spiro - MeOTAD ) as a hole transport material ( HTM ) are investigated using electrical impedance spectroscopy .
 Chemical: 2 , 2 ' , 7 , 7 ' - tetrakis ( N , N - di - p - methoxyphenylamine ) - 9 , 9 ' - spirobifluorene; Chemical: spiro - MeOTAD
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: 2 , 2 ' , 7 , 7 ' - tetrakis ( N , N - di - p - methoxyphenylamine ) - 9 , 9 ' - spirobifluorene; Chemical: spiro - MeOTAD