A large number of optoelectronic devices consist of a p-type and n-type region, as well as a regular p-n diode. The key difference is that there is an additional interaction between the electrons and holes in the semiconductor and the light. This interaction is not limited to optoelectronic devices. It is also known that regular diodes are sensitive to light and in some cases also emit light. The key difference is that optoelectronic devices such as photodiodes, solar cells, LEDs and laser diodes are specifically designed to optimize the absorption and emission of light, resulting in high conversion efficiency.