No circuit diagram, just a tiny home project. The solar panels collect to a DC Buck Converter that works at 0.9V to 7V input and outputs 5V 2A max via USB. Likely due to the losses, though, it can barely charge a flip phone, and not my 1+1 phone. Which is fine, that's it's purpose, but i'm told that if I use a schottky diode on each panel, it will prevent the panels from leaking current and discharging the battery at night, as well as improve the overall performance in the event of a failed or obscured panel so it doesn't block or significantly reduce output from other panels.
I am also told that if I used an LDO of some sort that it would better normalize the power for the buck converter and greatly improve efficiency.