A semiconductor is a solid material that has electrical conductivity between those of a conductor and an insulator; it can vary over that wide range either permanently or dynamically.[1]
Semiconductors are important in electronic technology. Semiconductor devices, electronic components made of semiconductor materials, are essential in modern consumer electronics, including computers, mobile phones, and digital audio players. Silicon is used to create most semiconductors commercially, but dozens of other materials are used.
Bragg reflection in a diffuse lattice
A second way starts with free electrons waves. When fading in an electrostatic potential due to the cores, due to Bragg reflection some waves are reflected and cannot penetrate the bulk, that is a band gap opens. In this description it is not clear, while the number of electrons fills up exactly all states below the gap.
Energy level splitting due to spin state Pauli exclusion
A third description starts with two atoms. The split states form a covalent bond where two electrons with spin up and spin down are mostly in between the two atoms. Adding more atoms now is supposed not to lead to splitting, but to more bonds. This is the way silicon is typically drawn. The band gap is now formed by lifting one electron from the lower electron level into the upper level. This level is known to be anti-bonding, but bulk silicon has not been seen to lose atoms as easy as electrons are wandering through it. Also this model is most unsuitable to explain how in graded hetero-junction the band gap can vary smoothly.
半導(dǎo)體是一種導(dǎo)電性能介于導(dǎo)體與絕緣體之間的固體材料。它能在此之間永久地或動(dòng)態(tài)地變化。
半導(dǎo)體在電子技術(shù)中有著非常重要的地位。半導(dǎo)體設(shè)備，由半導(dǎo)體材料制成的電子元件與現(xiàn)代消費(fèi)電子產(chǎn)品諸
如電腦，移動(dòng)電話和數(shù)位錄放音機(jī)等有著極為密切的關(guān)聯(lián)。硅是商業(yè)應(yīng)用上用做制造半導(dǎo)體的物質(zhì)，此外還有許多其他物質(zhì)也被用做制造半導(dǎo)體。
晶格中的布拉格反射
第二種說法是自由電子流。當(dāng)由于核的作用而導(dǎo)致靜電勢(shì)下降，因?yàn)椴祭穹瓷湟恍┳杂呻娮恿鞅环瓷涠荒艽┩福托纬闪艘粋€(gè)能帶隙。當(dāng)能量較低的價(jià)帶被電子完全填滿時(shí)，這種描述就不是那么清楚了。
由于自旋態(tài)包利不相容導(dǎo)致的能級(jí)分裂
第三種說法是兩個(gè)原子。分離抬形成一個(gè)兩個(gè)電子在兩個(gè)原子間的自旋的共價(jià)鍵。新增的原子不應(yīng)導(dǎo)致分裂，而是增加了價(jià)帶。這就是硅通常被提取的方法。能隙是由一個(gè)電子獲得能量從低能態(tài)跳躍至高能態(tài)而形成的。這一能態(tài)被認(rèn)為是反鍵。但是大量的硅并沒有像電子流動(dòng)一樣失去原子那么簡(jiǎn)單。同樣，這個(gè)模型也不適合去解釋在漸變抑制結(jié)中能隙是怎么樣順暢地變化。
能帶和導(dǎo)電