Semiconductor in physics, Lecture notes of Physics

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dsemisenduct ere ' PR Solids are the mate rials hoving definite shape and sixg on the ' basis of electrical Conductivity , solids con be classified as’ ° Conductors , These ye the solids which have high conductivi ky and low Fesishivity eg., all metals ) ° Insulator. ‘hest are Wu Solids whidn have low conductivity and high resish\uily « * Semi-conductors. These are the solids which have conduct vily ond vesisHvity intermdiate between conductors and — isuloctoys , Formation of Energy Bands in Solids | Db Eleclron im each atom hos their own erergy levels . In solids. there ave lavge rumber of atoms Aue do interaction of atomic energy — of eleedrons gel modified 4 winidh ‘6 the caus of leond foymetin, , ' Ener Nevelg are modified for valent ©& sinct ths. elections ore ws ation of encray levels for 'nntr._ eleckrovs - wm Considey a Silicon erustal tonsighing of N atoms, Si (z=u) , Elechronic configuration 116" 2s apt as? 3g » ’ & yi — shoved __bu different alow ond Hove Ye no appreciddle medifc y y y , b h For ths HN valence electrons there/Energy level] Avaliable | Oeenpied : . States States ave $N ovailoble energy states , 1s aN En _& The process of spli Hing of energy 2S aN aN i levels cop pe unddtstoad by Lonsider- 2 6N “6N ring diferent sifuotions o& Follouss : a Le aN " 3p 6M gn ki __ dy When ved , electrom in Hu outer” ; most shell of or atom do not interack with hos! of other. Hen trave % nd modification Sn evergy levels. : diy When c4véd , there 5 no visible Split ny, of energy levels. Ay When vec, “Wtevackion between — outermos} shell eleckrons Of radgrloousing Si atoms — Increakss and modifi cation o>) reat, oe) ca