Steps to make a solar cell phone charger

You can view items I used for my solar cell phone charger in this post. I am going to describe steps and  mistakes I did while making it.

1)  Soldered a diode to the positive terminal. Then soldered a wire to the diode. Mistake: I soldered the diode in a wrong direction. I discovered it only when the whole solar cell phone charger was made and it didn't charge the phone. The voltage on terminals under a lamp was 5 and more volts, but voltage in wires was 1.2 volts in every connection spots after terminals. Once the diode was soldered correctly, it started working. Here is an image of my initial soldering: 

        

 ...and a closer look at my mistake:

 

2) Soldered a blue wire to the negative terminal:

3) Cut a USB charger for my phone in half and stripped a black and a red wires. I twisted wires: blue to black (negative)

 and yellow to red (positive)

 4) Put tape over naked wires part to isolate them:

NOTE: check voltage in wires and diodes on EVERY soldering and connecting step with a multimeter! This will ensure you that the voltage is still strong and that all connections were done correctly.