Assertion: germanium's property | /r/HasProperty | to use thin films
Facets:
value: in order to decrease the cost efficiency ratio
type: PURPOSE
Source sentences:
text: Physically, the main property of a MJ solar cell is having more than one pn junction in order to catch a larger photon energy spectrum while the main property of the thin film solar cell is to use thin films instead of thick layers in order to decrease the cost efficiency ratio.