What is the difference between a CFL and an LED lamp?

1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semi-conductor material.
2. The average life span of a CFL is much longer than that of an LED lamp.
3. A CFL is less energy-efficient as compared to an LED lamp.

Which of the statement(s) given above is/are correct?

[UPSC Civil Services Exam – 2011 Prelims]

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (c)        

Explanation:

• The primary difference between the CFL and LED bulb is that LED bulbs are more durable and has a long life. Hence, statement 2 is incorrect.
• LED bulbs are much more efficient than CFL bulbs. Hence, statement 3 is correct.
• The main semiconductor materials used to manufacture LEDs are:
  • Indium gallium nitride (InGaN): blue, green, and ultraviolet high-brightness LEDs.
  • Aluminium gallium indium phosphide (AlGaInP): yellow, orange, and red high-brightness LEDs.
  • Aluminium gallium arsenide (AlGaAs): red and infrared LEDs. Hence, statement 1 is correct.