Isimiso esikhanyayo se-LED

Konkeisibani somsebenzi esingaphinde sishajwe, isibani sokukhempa esiphathwayofuthiisibani sekhanda esisebenza ngemisebenzi eminingiSebenzisa uhlobo lwebhalbhu ye-LED. Ukuze uqonde isimiso se-diode led, okokuqala kufanele uqonde ulwazi oluyisisekelo lwama-semiconductor. Izakhiwo zokuqhuba izinto ze-semiconductor ziphakathi kwama-conductor nama-insulator. Izici zayo ezihlukile yilezi: lapho i-semiconductor ivuselelwa ukukhanya kwangaphandle nezimo zokushisa, ikhono layo lokuqhuba lizoshintsha kakhulu; Ukwengeza inani elincane lokungcola ku-semiconductor emsulwa kukhulisa kakhulu ikhono layo lokuqhuba ugesi. I-Silicon (Si) ne-germanium (Ge) yiwona ama-semiconductor asetshenziswa kakhulu kuma-elekthronikhi anamuhla, futhi ama-electron awo angaphandle amane. Lapho ama-athomu e-silicon noma e-germanium akha ikristalu, ama-athomu angomakhelwane ayasebenzisana, ukuze ama-electron angaphandle abelwane ngama-athomu amabili, akha isakhiwo se-covalent bond kukristalu, okuyisakhiwo sama-molecule esinekhono elincane lokuvimbela. Ekushiseni kwegumbi (300K), ukuvuselela okushisa kuzokwenza amanye ama-electron angaphandle athole amandla anele okuhlukana nesibopho se-covalent abe ama-electron amahhala, le nqubo ibizwa ngokuthi ukuvuselela okungaphakathi. Ngemva kokuba i-electron ingaboshiwe ukuze ibe yi-electron yamahhala, isikhala sishiywa esibophweni se-covalent. Lesi sikhala sibizwa ngokuthi umgodi. Ukubonakala kwembobo kuyisici esibalulekile esihlukanisa i-semiconductor kumqhubi.

Uma inani elincane lokungcola kwe-pentavalent njenge-phosphorus lifakwa kwi-intrinsic semiconductor, lizoba ne-electron eyengeziwe ngemuva kokwakha isibopho se-covalent namanye ama-athomu e-semiconductor. Le electron eyengeziwe idinga amandla amancane kakhulu ukuze isuse isibopho futhi ibe yi-electron yamahhala. Lolu hlobo lwe-semiconductor yokungcola lubizwa ngokuthi i-electronic semiconductor (i-N-type semiconductor). Kodwa-ke, ukwengeza inani elincane lokungcola kwe-trivalent elemental (njenge-boron, njll.) kwi-intrinsic semiconductor, ngoba inama-electron amathathu kuphela kungqimba lwangaphandle, ngemva kokwakha isibopho se-covalent nama-athomu e-semiconductor azungezile, kuzodala isikhala ku-crystal. Lolu hlobo lwe-semiconductor yokungcola lubizwa ngokuthi i-hole semiconductor (P-type semiconductor). Lapho ama-semiconductor e-N-type kanye ne-P-type ehlanganiswa, kunomehluko ekugxilweni kwama-electron amahhala kanye nemigodi lapho kuhlangana khona. Womabili ama-electron kanye nemigodi asakazeka aye ekugxilweni okuphansi, ashiye ama-ion ashajekile kodwa angashukumi abhubhisa ukungathathi hlangothi kukagesi kokuqala kwezifunda ze-N-type kanye ne-P-type. Lezi zinhlayiya ezishajayo ezingashukumi zivame ukubizwa ngokuthi amashaji esikhala, futhi zigxile eduze kwendawo ehlanganayo yezifunda ze-N ne-P ukuze zakhe indawo encane kakhulu yeshaja yesikhala, eyaziwa ngokuthi i-PN junction.

Uma kusetshenziswa i-forward bias voltage kuzo zombili izinhlangothi ze-PN junction (i-voltage enhle kolunye uhlangothi lwe-P-type), imigodi nama-electron amahhala ahambahamba, okudala insimu kagesi yangaphakathi. Imigodi esanda kufakwa ibe isihlangana nama-electron amahhala, ngezinye izikhathi ikhipha amandla amaningi ngesimo sama-photon, okuwukukhanya esikubonayo okukhishwa ama-LED. I-spectrum enjalo incane kakhulu, futhi njengoba into ngayinye ine-band gap ehlukile, ubude bama-photon akhishwayo buhlukile, ngakho imibala yama-LED inqunywa yizinto eziyisisekelo ezisetshenziswayo.