[{"data":1,"prerenderedAt":138},["ShallowReactive",2],{"page-\u002F004":3},{"id":4,"title":5,"author":6,"body":7,"date":127,"description":128,"extension":129,"keywords":130,"lang":130,"meta":131,"navigation":133,"path":134,"seo":135,"stem":136,"titile":130,"update":130,"__hash__":137},"blogs\u002F004.md","The First Beam of LED","Yi Neng Chen",{"type":8,"value":9,"toc":118},"minimark",[10,15,25,29,34,37,45,58,62,69,77,81,88,92,112,115],[11,12,14],"h1",{"id":13},"the-first-beam-of-light-from-the-led","The first beam of light from the LED",[16,17],"iframe",{"width":18,"height":19,"src":20,"scrolling":21,"border":22,"frameBorder":21,"framespacing":23,"allowFullScreen":24},800,600,"\u002F\u002Fplayer.bilibili.com\u002Fplayer.html?isOutside=true&aid=116555245422835&bvid=BV1g95x6AEQn&cid=38257691981&p=1","no",0,"0","true",[26,27,28],"p",{},"The LED, which is now shining brilliantly, was discovered by accident in a laboratory more than 100 years ago. The people involved did not realize the significance of this great discovery and only published two brief passages in a scientific journal to describe the process of this accidental finding. Henry Joseph Round (1881–1966) was a typical 'cross-disciplinary genius.' He was not only the first person to discover the LED luminescence phenomenon but also one of the founders of radio technology (RCA).",[30,31,33],"h3",{"id":32},"_1-the-accidental-spark-in-the-laboratory","1. The \"Accidental Spark\" in the Laboratory",[26,35,36],{},"At that time, engineer H. J. Round from the United Kingdom was working at the Marconi Company, with his main task being the improvement of radio reception technology. The Marconi Company was the \"pioneer\" of radio communication. Founded in the UK, this company was the absolute leader in communication technology in the early 20th century, a position comparable to today’s “Apple-Huawei” duo.",[26,38,39,40,44],{},"One day in 1907, Round was testing a ",[41,42,43],"strong",{},"\"Cat's Whisker Detector\""," for radio detection. This device consisted of a fine metal wire (the cat's whisker) in contact with a silicon carbide (SiC, commonly called carborundum at the time) crystal and was an early prototype of a semiconductor diode.",[26,46,47,48,51,52],{},"In the dimly lit laboratory, Round attempted to apply a voltage between two contact points on the silicon carbide crystal to test its electrical conductivity. When the voltage reached about 10 volts, he was surprised to notice that near the contact point of the metal wire and the crystal, ",[41,49,50],{},"a faint yellow light was emitted",". When he increased the voltage further to 110 volts, the light grew brighter, and on some crystals, spots of green, orange, and blue light could also be observed.\n",[53,54],"img",{"alt":55,"src":56,"title":57},"The First Beam of Light from an LED","\u002Fimages\u002Fblog\u002F0001.png","LED Yellow Light",[30,59,61],{"id":60},"_2-a-text-message-that-changed-history","2. A Text Message That Changed History",[26,63,64,65,68],{},"The perceptive Landé realized that this was not ordinary incandescent light, but an unknown physical phenomenon. However, since semiconductor theory had not yet been established at the time (quantum mechanics was still in its infancy), he could not explain the principle theoretically and could only describe it as \"",[41,66,67],{},"a curious phenomenon",".\"",[26,70,71,72,76],{},"In 1907, he published a very short communication (only two paragraphs) in the magazine ",[73,74,75],"em",{},"Electrical World",", reporting this discovery to the editor. In the letter, he recorded the experimental phenomena in detail: the light always seemed to emanate from the negative electrode, and different crystals or contact points emitted different colors of light. He cautiously speculated that it might be related to thermoelectric effects and publicly sought references from the academic community regarding similar phenomena.",[30,78,80],{"id":79},"_3-the-forgotten-first-beam-of-light","3. The Forgotten 'First Beam of Light'",[26,82,83,84,87],{},"Unfortunately, because the light emitted by silicon carbide at the time was ",[41,85,86],{},"extremely weak"," (very low efficiency) and highly unstable, it could not compete with the mainstream incandescent bulbs of the period. Facing the dual difficulties of lacking theoretical support and practical prospects, Land himself tried to research it for several years, but ultimately had to give up. This significant discovery was then buried in the archives, lying dormant for nearly 20 years, until Soviet scientist Oleg Losev revived the research.",[30,89,91],{"id":90},"_4-historical-significance","4. Historical Significance",[93,94,95,106],"ul",{},[96,97,98,101,102,105],"li",{},[41,99,100],{},"The 'Zero Generation' of LEDs",": Land's discovery first confirmed the existence of ",[41,103,104],{},"electroluminescence"," in solid-state semiconductor materials. Although the term 'LED' did not exist at the time, this is recognized as the origin of LED technology.",[96,107,108,111],{},[41,109,110],{},"The Return of SiC",": Interestingly, silicon carbide (SiC), which was abandoned back then due to low efficiency, has now become a core material of third-generation semiconductors, playing a key role in high-frequency, high-temperature, and high-power devices (such as fast charging and new energy vehicles).",[26,113,114],{},"It has been a century since the first ray of light was emitted from an LED, and truly large-scale applications have only occurred in the past twenty years. A technology often goes through various twists and turns and the efforts of countless people from discovery to maturity.",[26,116,117],{},"Land's story tells us that many great technological revolutions often begin with an inadvertent 'curious glance' in the laboratory.",{"title":119,"searchDepth":120,"depth":120,"links":121},"",2,[122,124,125,126],{"id":32,"depth":123,"text":33},3,{"id":60,"depth":123,"text":61},{"id":79,"depth":123,"text":80},{"id":90,"depth":123,"text":91},"2026-05-09","In 1907, British engineer Henry Joseph Round made an accidental operation in his laboratory, which became the starting point of LED history. This was not a carefully planned experiment, but a typical \"serendipitous discovery.\"","md",null,{"style":132},"practical-guide",true,"\u002F004",{"title":5,"description":128},"004","8A2i7n7ZcLuDzNxhPmWri-c9zsrF-fkl3E_j1Hgqvg4",1780216618876]