No, the Martian Lagrangian point L1 is the only stable point that can be used. If you tried to move the blocker closer to the sun, the device would have to orbit faster than Mars. L1 is the point where the gravity of the sun and Mars cancel out.

The only other place you could have it would be directly on mars, where it would have to be much larger.

Can you use the solar power collector as light sail to nudge the orbit closer to the sun-side of L1. I would assume every km would help.