23606
In contrast , doping the ZnO did not change the performance of PbSe QD / ZnO solar cells .
 Chemical: ZnO; Chemical: PbSe; Chemical: ZnO
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: ZnO, PbSe, ZnO 
Answer:
 Chemical: ZnO; Chemical: PbSe; Chemical: ZnO