Research Paper on Diode
Light Emitting Diodes (LEDs)
ELE 432 Assignment # 3 Vijay Kumar Peddinti
Light Emitting Diodes Principle Synopsis: To explain the theory and the underlying principle behind the functioning of an LED Brief History: • The first known report of a light-emitting solid-state diode was made in 1907 by the British experimenter H. J. Round.
(material.eng.usm.my/stafhome/zainovia/EBB424e/LED1.ppt)
• • • • • •
In the mid 1920s, Russian Oleg Vladimirovich Losev independently created the first LED, although his research was ignored at that time. In 1955, Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys. Experimenters at Texas Instruments, Bob Biard and Gary Pittman, found in 1961 that gallium arsenide gave off infrared radiation when electric current was applied. Biard & Pittman received the patent for the infrared light-emitting diode. In 1962, Nick Holonyak Jr., of the General Electric Company and later with the University of Illinois at Urbana-Champaign, developed the first practical visiblespectrum LED. He is seen as the "father of the light-emitting diode". In 1972, M. George Craford, Holonyak's former graduate student, invented the first yellow LED and 10x brighter red and red-orange LEDs. Shuji Nakamura of Nichia Corporation of Japan demonstrated the first highbrightness blue LED based on InGaN. The 2006 Millennium Technology Prize was awarded to Nakamura for his invention.
Schematic:
Theory: A Light emitting diode (LED) is essentially a pn junction diode. When carriers are injected across a forward-biased junction, it emits incoherent light. Most of the commercial LEDs are realized using a highly doped n and a p Junction.
Figure 1: p-n+ Junction under Unbiased and biased conditions. (pn Junction Devices and Light Emitting Diodes by Safa Kasap)
To understand the principle, let’s consider an unbiased pn+ junction (Figure1 shows the pn+ energy band diagram). The
ELE 432 Assignment # 3 Vijay Kumar Peddinti
Light Emitting Diodes Principle Synopsis: To explain the theory and the underlying principle behind the functioning of an LED Brief History: • The first known report of a light-emitting solid-state diode was made in 1907 by the British experimenter H. J. Round.
(material.eng.usm.my/stafhome/zainovia/EBB424e/LED1.ppt)
• • • • • •
In the mid 1920s, Russian Oleg Vladimirovich Losev independently created the first LED, although his research was ignored at that time. In 1955, Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys. Experimenters at Texas Instruments, Bob Biard and Gary Pittman, found in 1961 that gallium arsenide gave off infrared radiation when electric current was applied. Biard & Pittman received the patent for the infrared light-emitting diode. In 1962, Nick Holonyak Jr., of the General Electric Company and later with the University of Illinois at Urbana-Champaign, developed the first practical visiblespectrum LED. He is seen as the "father of the light-emitting diode". In 1972, M. George Craford, Holonyak's former graduate student, invented the first yellow LED and 10x brighter red and red-orange LEDs. Shuji Nakamura of Nichia Corporation of Japan demonstrated the first highbrightness blue LED based on InGaN. The 2006 Millennium Technology Prize was awarded to Nakamura for his invention.
Schematic:
Theory: A Light emitting diode (LED) is essentially a pn junction diode. When carriers are injected across a forward-biased junction, it emits incoherent light. Most of the commercial LEDs are realized using a highly doped n and a p Junction.
Figure 1: p-n+ Junction under Unbiased and biased conditions. (pn Junction Devices and Light Emitting Diodes by Safa Kasap)
To understand the principle, let’s consider an unbiased pn+ junction (Figure1 shows the pn+ energy band diagram). The