Devices like solar cells, batteries, LEDs etc. are now an integral part of our lives. Technological advancements in these devices are in vogue, either to increase their performance or to find new applications for them. These advancements often trickle down to the search for better materials or efficient processes. The space of potential materials, operations, operating conditions is vast, and selecting the right combination thereof to achieve the desired characteristics is a knowledge intensive activity. A large amount of such device fabrication knowledge is available in the form of publications, patents, company reports. We present a decision support system built on top of systematically extracted knowledge from materials science literature. The extracted knowledge is represented as knowledge graphs conforming to an ontology that can be queried to make informed decisions during device fabrication. We applied our system to the emerging class of devices- perovskite solar cells and achieved good results.