Ihe Ọhụrụ Na-agbanwe Agbanwe - Silikọn Ojii
Silicon ojii bụ ụdị ihe silicon ọhụrụ nwere njirimara optoelectronic dị mma. Isiokwu a na-achịkọta ọrụ nyocha gbasara silicon ojii nke Eric Mazur na ndị nchọpụta ndị ọzọ mere n'afọ ndị na-adịbeghị anya, na-akọwapụta usoro nkwadebe na nhazi nke silicon ojii, yana ihe ndị dị na ya dịka nnabata, luminescence, mwepụta ubi, na nzaghachi spectral. Ọ na-egosikwa ojiji dị mkpa nke silicon ojii nwere ike itinye na ihe nchọpụta infrared, sel anyanwụ, na ngosipụta flat-panel.
A na-ejikarị kristal silicon eme ihe n'ụlọ ọrụ semiconductor n'ihi uru ya dịka ịdị mfe ịsacha, ịdị mfe nke doping, na iguzogide okpomọkụ dị elu. Agbanyeghị, o nwekwara ọtụtụ ihe ndọghachi azụ, dịka nnukwu ntụgharị nke ìhè a na-ahụ anya na infrared n'elu ya. Ọzọkwa, n'ihi nnukwu oghere band ya,silikọn kristalEnweghị ike ịmịnye ìhè site na ogologo ebili mmiri karịrị 1100 nm. Mgbe ogologo ebili mmiri nke ìhè ihe mberede karịrị 1100 nm, a na-ebelata oke nnabata na nzaghachi nke ihe nchọpụta silicon. A ga-eji ihe ndị ọzọ dị ka germanium na indium gallium arsenide chọpụta ogologo ebili mmiri ndị a. Agbanyeghị, ọnụ ahịa dị elu, ihe onwunwe thermodynamic na-adịghị mma na ịdị mma kristal, na enweghị nkwekọ na usoro silicon tozuru okè na-ebelata ojiji ha na ngwaọrụ dabere na silicon. Ya mere, ibelata ntụgharị uche nke elu silicon kristal na ịgbatị oke ebili mmiri nchọpụta nke fotodetectors dabere na silicon na silicon dakọtara ka bụ isiokwu nyocha na-ekpo ọkụ.
Iji belata ntụgharị nke elu silicon kristal, ejirila ọtụtụ ụzọ na usoro nnwale, dị ka photolithography, reactive ion etching, na electrochemical etching. Usoro ndị a nwere ike, ruo n'ókè ụfọdụ, gbanwee elu na ọdịdị dị nso nke silicon kristal, si otú a na-ebelatasilikọn ntụgharị elu. N'ime oke ìhè a na-ahụ anya, ibelata ntụgharị uche nwere ike ime ka nnabata dịkwuo elu ma melite arụmọrụ ngwaọrụ. Agbanyeghị, na ogologo ebili mmiri gafere 1100 nm, ọ bụrụ na enweghị ọkwa ike nnabata n'ime oghere eriri silicon, mbelata ntụgharị uche na-eduga naanị na mmụba nnyefe, n'ihi na oghere eriri nke silicon na-ebelata nnabata ya nke ìhè ogologo ebili mmiri. Ya mere, iji gbasaa oke ebili mmiri dị nro nke ngwaọrụ dabere na silicon na nke dakọtara na silicon, ọ dị mkpa ịbawanye nnabata photon n'ime oghere eriri ahụ ma na-ebelata ntụgharị elu silicon n'otu oge.
Na ngwụcha afọ 1990, Prọfesọ Eric Mazur na ndị ọzọ na Mahadum Harvard nwetara ihe ọhụrụ—silikọn ojii—n'oge nnyocha ha gbasara mmekọrịta nke laser femtosecond na ihe, dịka egosiri na Foto 1. Mgbe ha na-amụ ihe gbasara fotoelectric nke silicon ojii, Eric Mazur na ndị ọrụ ibe ya nwere ihe ijuanya ịchọpụta na ihe silicon a nwere obere nhazi nwere ihe pụrụ iche nke fotoelectric. Ọ na-amịkọrọ ihe fọrọ nke nta ka ọ bụrụ ìhè niile dị na nso-ultraviolet na nso-infrared (0.25-2.5 μm), na-egosipụta njirimara luminescence dị mma na nke dị nso-infrared na ihe onwunwe dị mma nke ikuku ubi. Nchọpụta a kpatara mmetụta na ụlọ ọrụ semiconductor, ebe magazin ndị bụ isi na-agba mbọ ịkọ akụkọ banyere ya. Na 1999, magazin Scientific American and Discover, na 2000 ngalaba sayensị Los Angeles Times, na na 2001 magazin New Scientist niile bipụtara akụkọ ndị na-atụle nchọpụta nke silicon ojii na ngwa ndị nwere ike ime, na-ekwere na ọ nwere uru dị ukwuu na mpaghara dịka nchọpụta anya, nkwukọrịta anya, na microelectronics.
Ugbu a, T. Samet si France, Anoife M. Moloney si Ireland, Zhao Li si Fudan University na China, na Men Haining si Chinese Academy of Sciences emeela nnyocha sara mbara na black silicon ma nweta nsonaazụ mbụ. SiOnyx, ụlọ ọrụ dị na Massachusetts, USA, enwetala ego ruru nde dọla iri na otu iji jee ozi dị ka ikpo okwu mmepe teknụzụ maka ụlọ ọrụ ndị ọzọ, ma malitekwa imepụta wafer silicon ojii dabere na sensọ, na-akwado iji ngwaahịa emechara na sistemụ infrared ọgbọ na-abịa. Stephen Saylor, CEO nke SiOnyx, kwuru na uru dị ala na nnukwu mmetụta nke teknụzụ silicon ojii ga-adọta uche nke ụlọ ọrụ lekwasịrị anya na nyocha na ahịa onyonyo ahụike. N'ọdịnihu, ọ nwere ike ọbụna banye n'ahịa igwefoto dijitalụ na kamera dijitalụ nke ruru ijeri dọla. SiOnyx na-anwalekwa ugbu a na ihe onwunwe fotovoltaic nke silicon ojii, ọ ga-abụkwa na o yikarịrị ka nke ahụsilikọn ojiia ga-eji ya mee ihe n'ime mkpụrụ ndụ anyanwụ n'ọdịnihu. 1. Usoro nhazi nke Silikọn Ojii
1.1 Usoro Nkwadebe
A na-eji trichlorethylene, acetone, na methanol hichaa wafer silicon otu kristal n'usoro, wee tinye ya n'elu ogbo ebumnuche atọ a na-ebugharị ebugharị n'ime ogbo ikuku. Nrụgide ntọala nke ogbo ikuku ahụ erughị 1.3 × 10⁻² Pa. Gas na-arụ ọrụ nwere ike ịbụ SF₆, Cl₂, N₂, ikuku, H₂S, H₂, SiH₄, wdg, yana nrụgide ọrụ nke 6.7 × 10⁴ Pa. N'aka nke ọzọ, enwere ike iji gburugburu ikuku, ma ọ bụ tinye ntụ ntụ nke S, Se, ma ọ bụ Te n'elu silicon n'ime ogbo ikuku. Enwere ike mikpuo ogbo ebumnuche ahụ na mmiri. A na-eji oghere anya nke Femtosecond pulses (800 nm, 100 fs, 500 μJ, 1 kHz) nke amplifier regenerative laser Ti:sapphire mepụtara na-elekwasị anya na oghere anya ma na-enwu gbaa n'akụkụ n'elu elu silicon (ike mmepụta laser na-achịkwa site na attenuator, nke nwere ọkara-ebili efere na polarizer). Site na ịkwaga ogbo ebumnuche iji nyochaa elu silicon site na ntụpọ laser, enwere ike nweta ihe silicon ojii buru ibu. Ịgbanwe anya dị n'etiti lenzi na wafer silicon nwere ike ịgbanwe nha nke ntụpọ ìhè nke a na-enwu na elu silicon, si otú a na-agbanwe mmetụta laser; mgbe nha ntụpọ ahụ na-agbanwe agbanwe, ịgbanwe ọsọ na-agagharị nke ogbo ebumnuche nwere ike ịgbanwe ọnụọgụ nke mkpali a na-enwu na mpaghara otu nke elu silicon. Gas na-arụ ọrụ na-emetụta ọdịdị nke obere nhazi elu silicon. Mgbe gas na-arụ ọrụ na-agbanwe agbanwe, ịgbanwe mmetụta laser na ọnụọgụ nke mkpali a na-enweta kwa mpaghara otu nwere ike ijikwa elu, oke akụkụ, na oghere nke obere nhazi.
1.2 Àgwà A Na-ahụ Anya Maka Anụmanụ
Mgbe e mechara ka ọ dị n'ihu laser femtosecond, elu silicon kristal dị nro nke mbụ na-egosipụta ọtụtụ obere ihe owuwu kọnịk nke a haziri nke ọma. Elu kọn dị n'otu ebe ahụ dị n'elu silicon a na-anaghị enwu gbaa gbara ya gburugburu. Ọdịdị nke ihe owuwu kọnịk metụtara gas na-arụ ọrụ, dịka egosiri na Foto nke 2, ebe ihe owuwu kọnịk egosiri na (a), (b), na (c) dị na ikuku SF₆, S, na N₂, n'otu n'otu. Agbanyeghị, ntụziaka nke elu kọn ahụ na-adabereghị na gas ma na-egosi mgbe niile na ntụziaka nke ihe omume laser, ọ dịghịkwa emetụta ike ndọda, ọ na-adabereghịkwa na ụdị doping, resistivity, na nhazi kristal nke silicon kristal; ntọala kọn ahụ adịghị nhata, yana axis dị mkpirikpi ha na ntụziaka laser polarization. Ihe owuwu kọnịk nke e kere n'ikuku bụ nke kachasị sie ike, elu ha kpuchikwara na nanostructures dendritic dị mma nke 10-100 nm.
Ka mmetụta laser na-arị elu ma na-amụbawanye ọnụọgụ nke mkpali, otú ahụ ka nhazi kọnịk na-adị ogologo ma na-agbasawanye. Na gas SF6, elu h na oghere d nke nhazi kọnịk nwere mmekọrịta na-abụghị nke kwụ ọtọ, nke enwere ike ịkọwa dị ka h∝dp, ebe p=2.4±0.1; ma elu h na oghere d na-abawanye nke ukwuu ka mmetụta laser na-abawanye. Mgbe mmetụta ahụ na-abawanye site na 5 kJ/m² ruo 10 kJ/m², oghere d na-abawanye site na ugboro atọ, ma jikọta ya na mmekọrịta dị n'etiti h na d, elu h na-abawanye site na ugboro iri na abụọ.
Mgbe a gbasasịrị okpomọkụ dị elu (1200 K, awa 3) n'ime oghere, nhazi kọnị ahụsilikọn ojiiMgbanweghị nke ukwuu, mana nhazi dendritic nke 10-100 nm dị n'elu belatara nke ukwuu. Ion channeling spectroscopy gosiri na nsogbu dị n'elu kọnịl ahụ belatara mgbe a na-eme ka ọ dị nro, mana ọtụtụ n'ime nhazi ndị a na-eme ka ọ dị nro agbanweghị n'okpuru ọnọdụ a na-eme ka ọ dị nro.
1.3 Usoro Nhazi
Ugbu a, usoro e ji emepụta silicon ojii edoghị anya. Agbanyeghị, Eric Mazur na ndị otu ya chepụtara, dabere na mgbanwe dị na ọdịdị nke microstructure elu silicon na ikuku ọrụ, na n'okpuru mkpali nke laser femtosecond dị elu, enwere mmeghachi omume kemịkalụ n'etiti gas na elu silicon kristal, na-ekwe ka ụfọdụ gas tee elu silicon ahụ, na-emepụta cones dị nkọ. Eric Mazur na ndị otu ya kwuru na usoro anụ ahụ na kemịkalụ nke nhazi microstructure elu silicon bụ: ịgbaze na iwepụ ihe mkpuchi silicon nke sitere na pulses laser dị elu; ịkụcha ihe mkpuchi silicon site na ions na ihe ndị na-emegharị ahụ nke ubi laser siri ike mepụtara; na ịmegharị akụkụ a gbapụrụ agbahapụ nke silicon substrate ahụ.
A na-emepụta usoro kọnịk dị n'elu silicon n'onwe ya, enwere ike ịmepụta usoro quasi-regular na-enweghị ihe mkpuchi ihu. MY Shen na ndị otu ya tinyere eriri ọla kọpa elektrọn nke nwere ọkpụrụkpụ 2 μm na elu silicon dị ka ihe mkpuchi ihu, wee jiri laser femtosecond laser mee ka silicon wafer dị na gas SF6 gbaa ọkụ. Ha nwetara usoro nhazi kọnịk dị iche iche a haziri nke ọma n'elu silicon, nke kwekọrọ na usoro ihe mkpuchi ihu (lee Foto 4). Nha oghere nke ihe mkpuchi ihu na-emetụta nke ukwuu nhazi nke usoro kọnịk. Mgbasa nke laser ihe merenụ site na oghere ihe mkpuchi ihu na-eme ka nkesa ike laser na-abụghị otu na elu silicon, na-ebute nkesa okpomọkụ oge niile na elu silicon. Nke a na-amanye usoro nhazi elu silicon ka ọ bụrụ nke nkịtị.