Kutheni i-silicon ilukhuni kangaka kodwa ibuthathaka kangaka?

I-siliconyikristale yeathomu, eneathomu ezidityaniswe ngezibopho ze-covalent, ezenza isakhiwo senethiwekhi yendawo. Kolu lwakhiwo, iibhondi ze-covalent phakathi kweeathomu zijolise kakhulu kwaye zinamandla aphezulu ebhondi, nto leyo eyenza i-silicon ibonise ubunzima obukhulu xa imelana namandla angaphandle ukutshintsha imo yayo. Umzekelo, kufuneka amandla amakhulu angaphandle ukutshabalalisa unxibelelwano oluqinileyo lwebhondi ye-covalent phakathi kweeathomu.

Nangona kunjalo, kungenxa yeempawu zesakhiwo eziqhelekileyo neziqinileyo zekristale yayo yeathomu ukuba xa iphantsi kwamandla amakhulu okubetha okanye amandla angaphandle angalinganiyo, i-lattice engaphakathii-siliconKunzima ukuyidibanisa nokusasaza amandla angaphandle ngokusebenzisa uguquko lwendawo, kodwa kuya kubangela ukuba ii-covalent bonds ziqhekeke kwezinye ii-crystal planes ezibuthathaka okanye kwiindlela zekristale, nto leyo eya kubangela ukuba lonke ulwakhiwo lwekristale luqhekeke kwaye lubonise iimpawu ezibuthathaka. Ngokungafaniyo nezakhiwo ezifana neekristale zesinyithi, kukho ii-ionic bonds phakathi kwee-athomu zesinyithi ezinokutyibilika ngokulinganiselayo, kwaye zinokuxhomekeka ekutyibilikeni phakathi kwee-athomu ukuze zivumelane namandla angaphandle, zibonisa ukuguquguquka okuhle kwaye kulula ukuqhekeka.

I-siliconiiathom ziqhagamshelwe zii-covalent bonds. Umongo wee-covalent bonds kukusebenzisana okuqinileyo okwenziwa zii-electron pairs ezabelwana ngazo phakathi kweeathom. Nangona olu qhagamshelo lunokuqinisekisa uzinzo kunye nobunzima be-ikristale yesiliconisakhiwo, kunzima ukuba i-covalent bond ibuyele kwimeko yayo yakuba iphukile. Xa amandla asetyenziswa lihlabathi langaphandle edlula umda onokuwunyamezela i-covalent bond, i-bond iya kuphuka, kwaye kuba akukho zinto ezifana nokuhamba ngokukhululekileyo kwee-electron ezifana neentsimbi ukunceda ukulungisa ukuqhekeka, ukuphinda uqalise unxibelelwano, okanye ukuxhomekeka ekususweni kwee-electron ukuze kusasazwe uxinzelelo, kulula ukuqhekeka kwaye ayinakugcina ingqibelelo iyonke ngokulungiswa kwayo kwangaphakathi, nto leyo ebangela ukuba i-silicon ibe buthathaka kakhulu.

Kwimisebenzi ebonakalayo, izinto zesilicon zihlala kunzima ukuzicoca ngokupheleleyo, kwaye ziya kuba neziphene ezithile kunye neziphene zelattice. Ukufakwa kweeathom zokungcola kunokuphazamisa ulwakhiwo lwelattice yesilicon oluqhelekileyo, okubangela utshintsho kumandla eekhemikhali zasekuhlaleni kunye nendlela yokubopha phakathi kweeathom, okubangela iindawo ezibuthathaka kwisakhiwo. Iziphene zelattice (ezifana nezithuba kunye nokudilika) nazo ziya kuba ziindawo apho uxinzelelo lugxininiswa khona.

Xa amandla angaphandle esebenza, la mabala abuthathaka kunye neendawo zoxinzelelo zinokubangela ukuqhekeka kwee-covalent bonds, nto leyo ebangela ukuba izinto ze-silicon ziqale ukuqhekeka kwezi ndawo, nto leyo ebangela ukuba zibe buthathaka ngakumbi. Nokuba ekuqaleni yayixhomekeke kwii-covalent bonds phakathi kwee-athomu ukwakha isakhiwo esinobunzima obuphezulu, kunzima ukuphepha ukuqhekeka okubuthathaka phantsi kwempembelelo yamandla angaphandle.