Temperature Effect of Conductivity

Temp effect on conductivity Cord. At OK is freeze at valence band ,80 insulators conductivity increases with valence increasing temp. as insulator conductor resistivity decreases. AL higher temp. / transition from valence bond to the conduction band gets facilitated higher conductivity or lower resilivity semi- conductor I E6 Eg Eg temp Ev Semi Extrinsic Intrinsic pure form of Ge, Si p-type n-type ne brivalent impurity pentavalent impurity P,AS,Sb etc. Ga,B,In, Al donor impurity -No donor impurity-No (nezzn) (mm)

Intrinsic Chemically very Bune 4 possesses poor conductivity Espect Has equal MO of holes (the carrier) Cy ( ve carmers/Bre is Extrinsic Improved extrinsic semiconductor with a small amount of impurities added by a process, known as doping which alters. the electrical properties of semiconductors cy improves conductivity Introducing imp unities into semiconductors materials can control conductivity. Available as either elements or compounds. Si Cy Ge common elemental semiconductors. InSb, INAS, Gap, Gasb, Gats, SiC Cy GaN. are compound SC.

notype Intrinsie DC. doped with pentavalent impurity such as P,As,Sb, etc. If a small amount of P is added to pure Si free to move around (free e) as surplus anystal / one of the valence is of P becomes i. Intrinsic sc doped with trivalent impurity p-type such as B,Al, In, etc. , If a small amount of B is doped insufficient to a single crystal of Si, valence is will be in at one position to bond Si cy B , resulting holes that lack is.