What is the Photovoltaic Effect?

What is PV? According to NREL, the “photovoltaic” or “PV” in short gets its name from the operating principle of PV cells, which is the photovoltaic effect [1]. The word photovoltaic is a combined term composed of “photo,” which suggests light or photons, and “voltaic,” which suggests the ability to produce electricity, hence the process of converting light into electricity. 

Alexandre-Edmond Becquerel, a French physicist, first observed the photovoltaic effect in 1839 when he attempted to create a current between two platinum and gold plates that were submerged in a solution and exposed to light [2]. In addition, what happens next is that the energy from the light is absorbed by the metal's valence band electrons, which, upon excitation, migrate to the conduction band and are thus free to move [2]. Then, a built-in junction potential or Galvani Potential accelerates these excited electrons to quickly move from one material to the other [2].

Voltage is generated from a charge difference, created when electrons move away from their parent material, while the moving electrons make up an electrical current [3]. Both voltage and current provide us with energy over time, making the photovoltaic effect in PV cells a pragmatic way to convert solar energy into electrical energy [3].

Imagine, a simple attempt by a scientist turned into a productive process that helps us produce efficient energy today. Because of this, things such as space satellites and smaller items like watches and calculators can be powered by solar cells [1]. As time goes by, the photovoltaic effect and advances in solar energy will greatly increase its advantages in the future.

References:

[1] “Solar Photovoltaic Technology Basics,” NREL.gov, https://www.nrel.gov/research/re-photovoltaics.html#:~:text=Solar%20cells%2C%20also%20called%20photovoltaic,is%20called%20the%20photovoltaic%20effect (accessed Aug. 3, 2023). 

[2] Admin, “Difference between photoelectric effect and photovoltaic effect,” Compare the Difference Between Similar Terms, https://www.differencebetween.com/difference-between-photoelectric-effect-and-vs-photovoltaic-effect/ (accessed Aug. 3, 2023). 

[3] G. Optics, “What is photovoltaics (PV) cells ?: G2v Optics,” G2V Optics Inc., https://g2voptics.com/photovoltaics-solar-cells/what-is-photovoltaics/ (accessed Aug. 3, 2023).