Solar Cell Spectral Response

Interactive Spectral Response Demonstration

The demonstration first sought to illustrate how white light is composed of a wide range of colours. An Xe lamp was concealed inside the cabinet and directed upwards through a hole in the surface. A mirror was used to direct the beam onto a large prism where the light was dispersed onto a movable stage. A very evident 'rainbow' of colours was apparent to the visitor.

To illusstrate how solar cells made from different semiconductors respond differently to different wavelengths of light, three solar cells of different band-gap energies (InGaP / GaAs / Silicon) were mounted vertically on a motorised stage that scanned them through the 'rainbow' of colours. Visitors could observe the response of each cell on a computer screen and were often surprised to see that two of the three cells were not just sensitive to visible light, but also infrared.