29605
Physi - sorbed O2 and / or H2O molecules electronically deplete n - type materials such as MoS2 and MoSe2 , which weakens electrostatic screening that would otherwise destabilize excitons , leading to the drastic enhancement in photoluminescence .
 Chemical: O2; Chemical: H2O; Chemical: MoS2; Chemical: MoSe2
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: O2; Chemical: H2O; Chemical: MoS2; Chemical: MoSe2