XPost: uk.d-i-y, alt.home.repair, alt.sci.physics   
   From: CFKinsey@military.org.jp   
      
   On Thu, 03 Oct 2019 14:29:30 +0100, Commander Kinsey  wrote:   
      
   > Why do LEDs generate heat? I want a technical answer not "because they're   
   inefficient". And will we ever make them more efficient?   
      
   I got useful answers from Quora:   
      
   "LEDs are ever more and more efficient. In the last 40 years, tremendous   
   strides have been made. They generate heat because they are conducting   
   electricity through semiconductors. Unlike metals which have very little   
   resistance to electric currents,    
   semiconductors offer more resistance. Not as much as true nonmetals, but still   
   more than metals. It is the resistance of the semiconductor layers, both N and   
   P, and the resistance of the junction itself, that generate the heat."   
      
   "Every electronic device is less than 100 percent efficient. On a low level,   
   it is due to the law of probability, or as the physicists call it, entropy.   
   The odds of all those electrons conveying their energy into photons is very   
   low. Some are always    
   making random transitions, generating heat instead of light."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)