Ka'idar haske ta LED

DukHasken aiki mai caji, hasken zango mai ɗaukuwakumaFitilar kai mai aiki da yawaYi amfani da nau'in kwan fitilar LED. Don fahimtar ƙa'idar diode led, da farko a fahimci ilimin semiconductors. Sifofin watsawa na kayan semiconductors suna tsakanin masu jagoranci da masu hana ruwa gudu. Sifofinsa na musamman sune: lokacin da semiconductor ya motsa ta hanyar haske da yanayin zafi na waje, ikon watsawa zai canza sosai; Ƙara ƙananan ƙazanta ga semiconductor mai tsabta yana ƙara ƙarfinsa na gudanar da wutar lantarki. Silicon (Si) da germanium (Ge) su ne semiconductors da aka fi amfani da su a cikin kayan lantarki na zamani, kuma electrons na waje su huɗu ne. Lokacin da silicon ko germanium atoms suka samar da lu'ulu'u, atoms maƙwabta suna hulɗa da juna, don haka electrons na waje su raba ta atoms biyu, wanda ke samar da tsarin haɗin covalent a cikin lu'ulu'u, wanda tsarin kwayoyin halitta ne wanda ba shi da ikon ƙuntatawa. A zafin jiki na ɗaki (300K), motsawar zafi zai sa wasu electrons na waje su sami isasshen kuzari don su rabu da haɗin covalent su zama electrons 'yanci, wannan tsari ana kiransa excitation na ciki. Bayan an cire electron don ya zama electron 'yanci, ana barin gurbi a cikin haɗin covalent. Ana kiran wannan gurbi rami. Bayyanar rami muhimmin abu ne da ke bambanta semiconductor da conductor.

Idan aka ƙara ƙaramin ƙazanta na pentavalent kamar phosphorus a cikin semiconductor na ciki, zai sami ƙarin electron bayan ya samar da haɗin covalent tare da sauran ƙwayoyin semiconductor. Wannan ƙarin electron yana buƙatar ƙaramin kuzari kawai don kawar da haɗin kuma ya zama electron kyauta. Wannan nau'in semiconductor na ƙazanta ana kiransa semiconductor na lantarki (N-type semiconductor). Duk da haka, ƙara ƙaramin adadin ƙazanta na trivalent elemental (kamar boron, da sauransu) zuwa semiconductor na ciki, saboda yana da electrons uku kawai a cikin layin waje, bayan ƙirƙirar haɗin covalent tare da ƙwayoyin semiconductor da ke kewaye, zai haifar da gurɓataccen wuri a cikin lu'ulu'u. Wannan nau'in semiconductor na ƙazanta ana kiransa hole semiconductor (P-type semiconductor). Lokacin da aka haɗa semiconductors na nau'in N da P, akwai bambanci a cikin yawan electrons kyauta da ramuka a mahaɗin su. Dukansu electrons da ramuka suna yaɗuwa zuwa ƙananan yawan, suna barin ions masu caji amma marasa motsi waɗanda ke lalata asalin tsaka tsaki na wutar lantarki na yankuna na nau'in N da P. Waɗannan ƙwayoyin da aka caji marasa motsi galibi ana kiransu da cajin sarari, kuma suna taruwa kusa da mahadar yankunan N da P don samar da yanki mai siriri na cajin sarari, wanda aka sani da mahadar PN.

Idan aka yi amfani da ƙarfin bias na gaba a ƙarshen duka mahadar PN (ƙarfin lantarki mai kyau zuwa gefe ɗaya na nau'in P), ramukan da electrons kyauta suna motsawa a kusa da juna, suna ƙirƙirar filin lantarki na ciki. Sabbin ramukan da aka allurar sannan su sake haɗuwa da electrons kyauta, wani lokacin suna fitar da makamashi mai yawa a cikin nau'in photons, wanda shine hasken da muke gani ana fitar da leds. Irin wannan bakan yana da ɗan kunkuntar, kuma tunda kowane abu yana da tazara daban-daban, tsawon raƙuman photons da aka fitar sun bambanta, don haka launukan leds ana ƙayyade su ta hanyar kayan da aka yi amfani da su.