Like Jeffrey says this are standard rectify diodes, and they are not photo. You probably mix this diodes with solar module bypass Schottky low voltage drop diodes from some solar circuit.
You can make solar panel from cheap garden solar lamps. You can make higher voltage and current, just put more this small modules in serie and parallel with bypass Schottky diodes.
Of course always is useful to hear and learn something new. If you find way to do this I'm ready to get this useful informations from you, if you want to share that with me. Always open for learning why not.