Product 110867. MRD 14B MRD14B MRD14 NPN The Darlington transistor is very sensitive to visible light. Base has standard "leg" to drive transistor if needed, transparent TO-92 enclosure. Light current typically 2uA, VCE 12V, dark current up to 100 nA at 12V.
Photodarlington as a microwave detector
https://ieeexplore.ieee.org/document/1451273
