Raws li cov qhab qhia kev tshawb fawb txog cov khib nyiab, cov theem zog ntawm cov khoom siv hluav taws xob hauv cov khoom siv hluav taws xob kom tsim tau band. Kev kub siab-zog conduction band, qis-zog valence band, ob cais pab pawg. Qhia cov khoom siv ua hluav taws xob tsis sib txig sib luag ntawm cov hluav taws xob-qhov hluav taws xob sib txuas, sib zog lub zog tso tawm rau hauv qhov pom kev ntawm lub teeb, qhov no yog qhov kev tso tawm rov qab.
Feem ntau muaj ob yam ntawm cov khoom siv semiconductor, cov khoom siv ncaj qha band-gap thiab cov khoom siv ncaj qha-band-gap, ncaj qha cov kis sib txawv semiconductors xws li GaAs (gallium arsenide) ntau ntau dua li tsis ncaj qha bandgap semiconductor cov ntaub ntawv xws li Si radiative hloov qhov yuav tshwm sim, luminous efficiency yog ntau dua.
Recombination nyob rau hauv semiconductors kom ua tiav emulated emission (lub laser) yog qhov tsim nyog rau kev ua raws li nram qab no: kev faib tawm ntawm cov pej xeem inversion los ntawm p-hom sab thiab n-hom sab rau hauv thaj av nquag thaum cov cab kuj muaj ntau, cov xov tooj ntawm cov hluav taws xob nyob hauv lub chaw sib cais. band electron Xeev ntau dua li cov xov tooj ntawm cov hluav taws xob nyob hauv qhov chaw ntaus nqi hluav taws xob Hauv Xeev, tsim kom muaj cov pejxeem inversion hauv kev faib tawm. ② lub teeb tsa rov ua kom zoo dua kab ntsig semiconductor lasers, kab noj hniav ua los ntawm cov iav nws ntawm ob qhov kawg, hu ua Fabry Perot kab noj hniav. Thib peb, siab nce nyiaj rau poob. Optical poob ntawm lub resonator feem ntau yog los ntawm qhov xav txog-tso tawm sab nraud tso ntawm poob thiab nruab nrab lub teeb haum.