How to Make Solar Cells using Transistors (2N3055)

It’s easy to cut open a power transistor like the 2N3055 to expose the NPN silicon material inside to make a solar cell. When exposed to sunlight, or household lights, it conducts electricity. The N-type and P-type materials work like a solar cell. The best way is from the Base to the Collector though from both the Base and Emitter combined and then to the Collector also works well. The voltage and current aren’t much but with just a few of them in series you can power a small 1.5 volt calculator. See also: See my “Make Solar Cell Transistor Powered Calculator using 2n3055” video where I make a solar panel out of these cells to power a calculator: Follow me on Twitter: –
Video Rating: 4 / 5

:: build solar power ::


  1. becoz im tried to make salted water energy but the voltage is quickly goes down and stay in low voltage..even i put more cup with salted water the voltage is increasing but just a little… now i want to try your idea by´╗┐ using solar energy thanks a lot sir i really appreciate ­čÖé

  2. Yes, if you connect the transistors in series then each transistor will add more voltage. For example you could connect the 1st transistor’s collector to the 2nd transistor’s base, and then the 2nd transistor’s collector to the 3rd one’s base, and so on.

    See my other video “Make Solar Cell Transistor Powered Calculator using 2n3055” where I do it with five transistors. There’s a link to it´╗┐ in the description below this video or you can find it on my channel.

  3. That error was caught already. Turn on annotations and you’ll see an annotation at 0:57 in the video with the´╗┐ correct designations.

  4. No not really,´╗┐ I only get about a couple of hundred millivolts at the most, if I had a whole bunch of them I might have tried that.

  5. Ahhh! How’d I mess that up? I’ll add an annotation. Thanks. Good catch. Good thing I didn’t use that´╗┐ diagram into my other video too.

  6. That is actually a good idea for an experiment ( : I will have to pick up a 2n3055 transistor during the week and I will see if infra-red light has the same effect as visible light on the readings. My infra-red array puts out just over 3 watts of light (including the current limiting I put´╗┐ in place).

    I’ll message you when the video is up (probably toward the end of next week).


  7. Thanks. It’d be interesting to see voltage and current measurements with your´╗┐ infra-red light.

  8. Some asked “Very nice find. Have you tried any other wavelength specific to determine optimal Lambda for current and´╗┐ voltage?”

    Infra red works very well on silicon junctions. Did anyone know you could also use a light emitting diode to generate current the same way you did here?

  9. No criticism intended. The problem is with this current flow business it works two ways. Conventional semiconductor theory says positive to negative while the military and electricity books teach negative to positive. So in a way you were correct. I teach electron theory.

    The .5 volts is the most you can get out of any silicon PN junction. The current is´╗┐ related the surface area of the junction. So a regular solar cell is a giant PN junction.

    Good video none the less.

  10. I was referring to the electron flow through the meter… though looking at the video now I can see how you might have thought I mean through the transistor… and then there’s the way I said it. Oops. I’ll add an annotation.

    Thanks for the thumbs up. I’ve had your Arduino videos bookmarked for this weekend… starting to go through them now.

    And re the .5 volts, I didn’t know that. Interesting. At least these transistors come close to´╗┐ the limit.

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