A band ka'idar daskararru. Jimla makanikai for dummies

Wannan talifin ya bayyana ma'anar band ka'idar daskararru. Nuna, abin da shi ne dalilin shi ne misali na tsarin kwayoyin halitta. Sakamako na karafa daban-daban daga dielectrics da semiconductors.

Rosette da Button

Sau nawa a rana za mu danna kan daban-daban mashiga? Babu daya ko tunani ya zo ba zai iya ƙidaya shi - ya zama haka saba da wannan aiki. Kuma mutum ba ya zaton cewa duk da wannan ne kawai zai yiwu godiya ga yadda sauki shi ne dauke da lantarki a karafa. Kunna hasken, tafasa sintali, gudu da Injin, ba a ma maganar da ayyuka a kan wayoyin salula na zamani, yana nufin kammala kewaye da damar da electrons a conductors aiki maimakon mutane. Bayani na irin mamaki a matsayin watsin sa. A mafi fili, watakila, shi ne band ka'idar daskararru.

Atom kuma kafaffu

Kowane mutum, wanda yake a makarantar sakandare, yana da wani ra'ayin na da tsarin da zarra. Ka tuna a kusa da wani lallai cajin nauyi tsakiya (kunshi protons da neutrons) juya huhu kadan electrons. Number of korau barbashi daidai daidai da dama tabbatacce. Domin kada ya huda masu karatu, bayyana a cikin style of "jimla makanikai for dummies." Kowane electron kewayewa ne tsananin iyakance, ga abin da shi za a iya juya a kusa da zuciyar a ba sinadari. Bi da bi, kowane jinsin yana da wani musamman juna kwayoyin halitta irin falakinsu. Yana da aka haka spectroscopists masana kimiyya rarrabe boron daga selenium da arsenic daga sodium. Duk da haka, ban da m abubuwa a yanayi, akwai wani iyaka yawan daban-daban haduwa. Jimla makanikai (for dummies, mai karatu ya tuna) ya bayar da hujjar cewa a cikin hadaddun mahadi falakinsu rarraba, ci, canza, ya miƙa, samar da wani haɗi. Su quality ya dogara da irin: covalent da ionic karfi, hydrogen, misali, shi ne mafi rauni.

crystal tsarin

The m jiki ne mafi wuya. Domin model, wanda yayi amfani da band ka'idar daskararru, yawanci dauki wani m crystal. Wannan yana nufin cewa shi ne m, kuma ba tare da zunubi - kowane zarra a kan kansa wuri, jimlar cajin ne sifili. Kwaya canza a kusa da wani musamman matsayi na ma'auni, amma electrons iya ce baki] aya. Ya danganta da yadda "sauki" daya zarra donates ta m korau gaɓũɓuwa, shi ne samu rigidly qaddara lantarki tsarin dielectrics ko karafa girgije. Na kamata ƙara da cewa idan akai la'akari da shi ne a zaci cewa duk electrons zauna da mafi ƙarancin adadin makamashi zuwa gare su, wanda ke nufin cewa jiki shi ne a sifili Kelvin. A mafi girma yanayin zafi, da mawadãta daga oscillation matsayin nuclei da electrons karfi da kuma, Saboda haka, da karshen ne iya zauna mafi girma makamashi matakan. Korau barbashi rarraba zama mafi "sako-sako da". A wasu matsaloli, yana da muhimmanci, duk da haka, bayyana wannan sabon abu kamar yadda irin wannan zafin jiki ne ba haka muhimmanci.

Pauli manufa da kuma Loader

A ra'ayi na band ka'idar daskararru za a iya isa kawai kyau zuwa tuna abin da Pauli manufa. Idan muka kwatanta da cewa electrons - mai jakar na sugar, sa'an nan, idan wadannan jakunkuna mai yawa, matukar Loader za su gabatar a kan juna. Kowane "jakar" daukan ta wuri a cikin sarari. Domin electrons, wannan yana nufin cewa, a wa jihar ne kawai wanda zai iya zama a daya tsarin. Wannan ne Pauli wariya manufa. Lura da cewa muna da tunani da manufa yanayi, watau zazzabi na sifili Kelvin, da kuma iyaka crystal. A dukan tsarin ne a cikin wannan yanayi na zafin jiki, inji danniya, lahani ne guda a dukkan sassa na dukan.

Lantarki lu'ulu'u zone

A crystal, a jam'i na daya irin sunadaran. Daya mole na abu qunshi wani goma zuwa ashirin da uku mataki abubuwa. Yadda yawa moles da kilogram, misali, gishiri? Saboda haka za ka iya ma ce cewa har ma da karami crystal ƙunshi unimaginably yawa kwayoyin halitta. Kowane sinadari na da juna na electron falakinsu, da kuma abin da ya yi, idan sun kasance a cikin jiki daya 'yan? Bayan duk, bisa ga Pauli wariya manufa, dole ne su zauna daban-daban jihohi. Band ka'idar daskararru offers da wadannan hanya - da electron falakinsu zama daban-daban kuzari. Bambanci tsakanin su ne don haka kananan cewa suna matse, ya jingina a juna sosai tam samar da wata m zone. Saboda haka, duk matakin da electron a zarra ne tuba a cikin wani sashi a cikin girma crystal. Abubuwa na band ka'idar daskararru iya taimaka bayyana bambanci tsakanin insulators da conductors.

Lantarki a cikin Shiyyar

Mun riga tattauna abin da ke faruwa tare da wani yawa na electrons, wanda a zarra zauna guda madawwama biyu, da samuwar na ƙarau. Amma da hali a ciki da zone har muka bar unlit. Raba wannan riga muhimmanci saboda shi kayyade bambanci tsakanin karafa da kuma wadanda ba karafa. Kamar yadda riga aka ambata a sama, da band ka'idar daskararru nuna cewa makamashi matakan cikin ƙungiyar mutum kwayoyin halitta daban-daban falakinsu bambanta haka kadan da cewa kusan samar da wata m bakan. Saboda haka, cin nasara da m shãmaki a tsakãnin electron ba wuya - shi motsa su sosai, domin wannan shi ne isa ko da kadan. Duk da haka, kowace daga cikin yarda band yana da iyaka. Babu ko da yaushe wani makamashi matakin da cewa shi ne mafi girma ko ƙananan fiye da wasu.

Valence haramta, watsin

Tsakanin wadannan zones da wani yanki na samar da makamashi, inda babu wani matakin a wanda wani electron iya zama. A jadawalai, ta bayyana a matsayin wani farin rata. Kuma ta kira band rata. Don shawo kan wannan shãmaki electron iya kawai jerk. Saboda haka, dole ne ya samu dace da wannan makamashi. A zone da mafi girma da makamashi, wanda ga irin wannan kwayoyin halitta halatta wanzuwar electrons da ake kira valence band, da kuma bin shi - watsin.

Metal dielectric

Madugu band ka'idar daskararru kula da cewa gaban ko babu electrons a madugu band ya nuna yadda sauƙi gudana a cikin wannan halin yanzu abu. Kamar wancan ne daban-daban karafa da kuma dielectrics. A cikin tsohon harka, da madugu band riga ya ƙunshi electrons, tun overlaps da valence. A wajen korau barbashi su kyauta matsawa karkashin mataki na electromagnetic filin, ba tare da wani ƙarin makamashi labari. Saboda haka, lantarki a karafa bayyana haka sauki, a gaskiya - nan take, da zaran cikin filin. Kuma ga wannan dalili, da waya da aka yi da karfe, tagulla, aluminum.

Materials for wanda da valence da kuma madugu makada rabu da wani makamashi-kira dielectrics. Wadannan electrons sun makale a cikin ƙananan matakin halatta. Band rata raba korau barbashi daga cikin matakin a cikin abin da suka iya matsar kusa da yardar kaina. Kuma da makamashi da cewa dole ne a sanar da electrons zuwa rinjaye shi, ya hallakar da kayan. Ko canza da kaddarorin bayan fitarwa. Saboda haka, filastik kunsa wayoyi narke da konewa, amma ba ya gudanar da wutar lantarki.

semiconductors

Amma akwai wani tsaka-tsaki aji na kayan da suke da wata bandgap, amma a karkashin wani yanayi na iya gudanar da wutar lantarki. Suna da ake kira - semiconductors. Kamar dielectric, suna da wani makamashi rata tsakanin madugu kuma valence. Duk da haka, shi ne kasa da kuma shawo kan tare da wasu kokarin. Gargajiya semiconductor ne silicon (a Latin - Silicium). Shahararren Silicon Valley ne sananne ga fasahar dogara ne a kan yin amfani da lu'ulu'u da wannan abu ne ya haifar da na'urorin lantarki.