Solar cells convert sunlight into electricity by using the photoelectric effect where electrons are excited by photons and produce an electric current. Albert Einstein discovered this phenomenon in 1905 and won the Nobel Prize for it. Solar cells use materials that absorb different wavelengths of light to generate electricity, with compounds able to use multiple bands for greater efficiency. While efficiency has improved over decades of research, more advancement is still needed to perfect solar cell technology.

1. Solar Cells – What are they really..?
- Subbu R Subramanian

2. The Photo Electric Effect
When light waves of appropriate wave length hit an atom, the
electrons of the atom get excited. The excited electrons jump out of the
orbit, making the atom an ion. This movement of Electrons causes
Electric Current.
Albert Einstein found this phenomenon in 1905. He was awarded
Nobel Price for Physics for this finding.

3. •Different element’s atoms get excited with different wave
lengths of light . (different colour lights )
Ex : Sodium with yellow band light, Potassium with green
band etc

4. Various Wave Length Bands of the Spectrum

5. The “Catchments Area” for the Solar Cells.

6. Compounds can make use of the Energy
in Multiple wave bands

7. UV side of the spectrum gives better power than IR

8. The Anatomy of a Solar Cell

9. The Path the Technology traveled in the past
Decades and its Current Efficiency Status

10. ...a lot needs to be done in perfecting PV cells……
...and the road ahead…