Qhov sib txawv tseem ceeb ntawm valence band thiab conduction band yog tias valence band muaj nyob hauv qab qib Fermi thaum lub conduction band muaj nyob saum qib Fermi.
Valence band thiab conduction band yog ze tshaj rau qib Fermi. Cov qhab no yog li txiav txim siab qhov hluav taws xob conductivity ntawm cov khoom siv. Fermi theem tshuaj muaj peev xwm rau electrons ntawm lub cev yog lub thermodynamic ua hauj lwm yuav tsum tau ntxiv ib electron rau lub cev.
Valence Band yog dab tsi?
Lub valence band yog electron band uas cov electrons tuaj yeem dhia tawm thaum lub atom zoo siab. Ntawm no, cov electrons dhia mus rau lub conduction band. Yog li ntawd, qhov tseem ceeb, nws yog qhov sab nraud ntawm electron orbital ntawm ib lub atom ntawm txhua yam khoom uas muaj electrons hauv nws. Ntxiv mus, lo lus no yog ze ze rau lo lus "valence electron".
Kev coj ua Band yog dab tsi?
Cov kab hluav taws xob yog ib pawg delocalized ntawm qib zog hauv cov khoom siv crystalline uas yog ib feem ntawm cov khoom siv hluav taws xob. Cov electrons no muaj kev txav mus los zoo thiab muaj lub luag haujlwm rau hluav taws xob conductivity. Ntawm no, lub conduction band yog band ntawm electron orbitals uas cov electrons tuaj yeem dhia thaum lub atom zoo siab. Cov electrons no dhia los ntawm valence band. Thaum cov electrons nyob rau hauv cov conduction band, cov electrons muaj lub zog txaus txav mus rau hauv ib yam khoom. Qhov kev txav no tsim hluav taws xob.
Daim duab 01: Daim duab qhia txog Kev Coj Ua Band thiab Valence Band
Lub bandgap yog lub zog sib txawv ntawm lub zog siab tshaj plaws nyob hauv lub xeev ntawm valence band thiab lub zog qis tshaj plaws ntawm lub zog ntawm qhov kev coj ua. Lub bandgap qhia txog hluav taws xob conductivity ntawm cov khoom. Qhov ntawd yog; ib lub bandgap loj txhais tau tias peb xav tau ntau lub zog los ua kom muaj hluav taws xob (los ntawm valence band mus rau conduction band). Thiab yog li, hluav taws xob conductivity tsawg.
Dab tsi yog qhov txawv ntawm Valence Band thiab Conduction Band?
Valence band yog cov electron bands uas cov electrons tuaj yeem dhia tawm thaum lub atom zoo siab. Meanwhile, lub conduction band yog ib tug delocalized band ntawm lub zog theem nyob rau hauv ib tug crystalline khoom uas yog ib feem ntawm cov electrons. Qhov sib txawv tseem ceeb ntawm valence band thiab conduction band yog tias valence band muaj nyob rau hauv qab theem fermi thaum lub conduction band nyob saum toj no theem Fermi.
Ntxiv mus, thaum lub atom ua rau zoo siab vim muaj lub zog, cov electrons zoo li dhia mus rau hauv cov kab hluav taws xob los ntawm valence band. Nws yog vim hais tias cov conduction band nyob rau hauv lub xeev siab zog thiab valence band nyob rau hauv ib tug tsawg zog xeev.
Summary – Valence Band vs Conduction Band
Lub valence band yog electron band uas cov electrons tuaj yeem dhia tawm thaum lub atom zoo siab. Tab sis, lub conduction band yog ib tug delocalized band ntawm lub zog theem nyob rau hauv ib tug crystalline khoom uas yog ib feem ntawm cov electrons. Yog li, qhov sib txawv tseem ceeb ntawm valence band thiab conduction band yog tias valence band muaj nyob rau hauv qab theem fermi thaum lub conduction band nyob saum toj no Fermi.
