
Given the following passage

"In recent years light emitting diodes (LEDs) are becoming increasingly efficient leading to an extraordinary increase in the use of solid state lighting. In many situations, controlling the light emission of LEDs may be done most effectively by using the principles of nonimaging optics.",

answer the following question. Note that the answer is present within the text.

Question: Two terminals components that produces a current in one direction are called? 

diodes
