Before finalizing the circuit, It is always a good idea to prototype the circuit on a breadboard. This lets you check to make sure that all of your components are working perfectly.

Make the circuit on your bread bard as per the schematic. The LED should not glow if the circuit is correct. To simulate the dark condition, cover the solar panel with your palm. Now the LED should glow.

To check the performance of the circuit, remove the LED and hook up the oscilloscope probes.

You will observe that the output is not a steady DC voltage rather it fluctuates rapidly. In my case, the frequency is around 184.5 kHz. The peak to peak voltage is nearly 7.28 V and the average value is around 1.0 to 1.20V.

Note: If you try to measure the voltage by a normal multimeter, it will show near to your battery voltage.Because your meters only measure the average value of a fluctuating voltage.