He Mea Hou Kipi - Silicon ʻEleʻele
He ʻano hou ka silicon ʻeleʻele o ka mea silicon me nā waiwai optoelectronic maikaʻi loa. Hōʻuluʻulu kēia ʻatikala i ka hana noiʻi ma ka silicon ʻeleʻele na Eric Mazur a me nā mea noiʻi ʻē aʻe i nā makahiki i hala iho nei, e hōʻike ana i ke ʻano hoʻomākaukau a me ke ʻano hana o ka silicon ʻeleʻele, a me kona mau waiwai e like me ka absorption, luminescence, field emission, a me ka pane spectral. Kuhikuhi pū ia i nā noi koʻikoʻi o ka silicon ʻeleʻele i nā mea ʻike infrared, nā cell solar, a me nā hōʻikeʻike pālahalaha.
Hoʻohana nui ʻia ka silicon crystalline i ka ʻoihana semiconductor ma muli o kona mau pono e like me ka maʻalahi o ka hoʻomaʻemaʻe ʻana, ka maʻalahi o ka doping, a me ke kūpaʻa wela kiʻekiʻe. Eia nō naʻe, he nui nā hemahema, e like me ke kiʻekiʻe o ka reflectivity o ke kukui ʻike ʻia a me ka infrared ma kona ʻili. Eia kekahi, ma muli o kona band gap nui,silika kristalaʻAʻole hiki ke omo i ka mālamalama me nā nalu ʻoi aku ma mua o 1100 nm. Ke ʻoi aku ka nalu o ka mālamalama i ka 1100 nm, ua emi nui ka omo ʻana a me ka pane ʻana o nā mea ʻike silicon. Pono e hoʻohana ʻia nā mea ʻē aʻe e like me ka germanium a me ka indium gallium arsenide e ʻike i kēia mau nalu. Eia nō naʻe, ʻo ke kumukūʻai kiʻekiʻe, nā waiwai thermodynamic maikaʻi ʻole a me ke ʻano kristal, a me ka kūlike ʻole me nā kaʻina hana silicon makua e kaupalena ana i kā lākou noi i nā mea hana silicon. No laila, ʻo ka hōʻemi ʻana i ka hoʻomālamalama ʻana o nā ʻili silicon crystalline a me ka hoʻonui ʻana i ka laulā nalu ʻike o nā photodetectors silicon-based a me silicon-compatible e mau nei i kumuhana noiʻi wela.
No ka hōʻemi ʻana i ke ʻano o nā ʻili silicon crystalline, ua hoʻohana ʻia nā ʻano hana hoʻokolohua he nui, e like me ka photolithography, reactive ion etching, a me ka electrochemical etching. Hiki i kēia mau ʻenehana, i kekahi ʻano, ke hoʻololi i ke ʻano o ka ʻili a me ka ʻili kokoke o ka silicon crystalline, a pēlā e hōʻemi ai.silika ka hoʻākāka ʻana o ka ʻili. I ka laulā kukui ʻike ʻia, hiki i ka hōʻemi ʻana i ka hoʻākāka ke hoʻonui i ka omo ʻana a hoʻomaikaʻi i ka pono o ka hāmeʻa. Eia nō naʻe, ma nā nalu e ʻoi aku ana ma mua o 1100 nm, inā ʻaʻohe pae ikehu omo i hoʻokomo ʻia i loko o ka hakahaka hui silicon, ʻo ka hoʻēmi ʻana o ka hoʻākāka e alakaʻi wale i ka hoʻonui ʻana i ka hoʻoili ʻana, no ka mea, ʻo ka hakahaka hui o ka silicon e kaupalena hope loa i kona omo ʻana i ke kukui nalu lōʻihi. No laila, no ka hoʻonui ʻana i ka laulā nalu koʻikoʻi o nā hāmeʻa e pili ana i ka silicon a me nā mea e kūpono ana i ka silicon, pono e hoʻonui i ka omo photon i loko o ka hakahaka hui me ka hōʻemi ʻana i ka hoʻākāka ʻana o ka ʻili silicon.
I ka hopena o nā makahiki 1990, ua loaʻa iā Polofesa Eric Mazur a me nā poʻe ʻē aʻe ma ke Kulanui ʻo Harvard kahi mea hou—silicon ʻeleʻele—i kā lākou noiʻi ʻana i ka launa pū ʻana o nā lasers femtosecond me nā mea, e like me ka mea i hōʻike ʻia ma ke Kiʻi 1. ʻOiai e aʻo ana i nā waiwai photoelectric o ka silicon ʻeleʻele, ua kāhāhā ʻo Eric Mazur a me kāna mau hoa hana i ka ʻike ʻana he mau waiwai photoelectric kūikawā kēia mea silicon microstructured. Hoʻopili ia i ka aneane āpau o ka mālamalama ma ka pae kokoke-ultraviolet a me ka infrared kokoke (0.25–2.5 μm), e hōʻike ana i nā ʻano luminescence ʻike maikaʻi loa a kokoke-infrared a me nā waiwai hoʻokuʻu kahua maikaʻi. Ua hoʻoulu kēia ʻike i kahi manaʻo i ka ʻoihana semiconductor, me nā makasina nui e hoʻokūkū nei e hōʻike ma luna. I ka makahiki 1999, ua paʻi nā makasina Scientific American a me Discover, i ka makahiki 2000 ka ʻāpana ʻepekema ʻo Los Angeles Times, a i ka makahiki 2001 ʻo ka makasina New Scientist i nā ʻatikala hiʻohiʻona e kūkākūkā ana i ka ʻike ʻana o ka silicon ʻeleʻele a me kāna mau noi hiki, me ka manaʻo he waiwai nui kona i nā kahua e like me ka ʻike mamao, nā kamaʻilio optical, a me ka microelectronics.
I kēia manawa, ua hana ʻo T. Samet mai Palani, ʻo Anoife M. Moloney mai ʻIlelani, ʻo Zhao Li mai ke Kulanui ʻo Fudan ma Kina, a me Men Haining mai ka Chinese Academy of Sciences i kahi noiʻi nui e pili ana i ka silicon ʻeleʻele a ua loaʻa nā hopena mua. ʻO SiOnyx, kahi hui ma Massachusetts, USA, ua hōʻiliʻili i $11 miliona ma ke kapikala hoʻopukapuka e lawelawe ma ke ʻano he kahua hoʻomohala ʻenehana no nā hui ʻē aʻe, a ua hoʻomaka i ka hana kalepa o nā wafers silicon ʻeleʻele i hoʻokumu ʻia i ka sensor, e hoʻomākaukau ana e hoʻohana i nā huahana i hoʻopau ʻia i nā ʻōnaehana kiʻi infrared hanauna e hiki mai ana. Ua ʻōlelo ʻo Stephen Saylor, Luna Nui o SiOnyx, ʻo ke kumukūʻai haʻahaʻa a me nā pono kiʻekiʻe o ka ʻenehana silicon ʻeleʻele e huki mau i ka manaʻo o nā hui e kālele ana i ka noiʻi a me nā mākeke kiʻi lapaʻau. I ka wā e hiki mai ana, hiki paha iā ia ke komo i ka mākeke kāmela kikohoʻe a me ka camcorder multi-billion kālā. Ke hoʻāʻo nei ʻo SiOnyx i kēia manawa me nā waiwai photovoltaic o ka silicon ʻeleʻele, a he mea hiki loa ia.silika ʻeleʻelee hoʻohana ʻia i loko o nā cell solar i ka wā e hiki mai ana. 1. Ke Kaʻina Hana o ka Silicon ʻEleʻele
1.1 Kaʻina Hoʻomākaukau
Hoʻomaʻemaʻe ʻia nā wafers silicon kristal hoʻokahi i kēlā me kēia manawa me ka trichloroethylene, acetone, a me ka methanol, a laila kau ʻia ma luna o kahi kahua pahuhopu hoʻoneʻe ʻekolu-dimensional i loko o kahi keʻena vacuum. ʻO ke kaomi kumu o ke keʻena vacuum he emi ma mua o 1.3 × 10⁻² Pa. Hiki i ke kinoea hana ke SF₆, Cl₂, N₂, ea, H₂S, H₂, SiH₄, a pēlā aku, me ke kaomi hana o 6.7 × 10⁴ Pa. Ma kekahi ʻaoʻao, hiki ke hoʻohana ʻia kahi wahi vacuum, a i ʻole hiki ke uhi ʻia nā pauka elemental o S, Se, a i ʻole Te ma luna o ka ʻili silicon i loko o kahi vacuum. Hiki nō hoʻi ke hoʻokomo ʻia ke kahua pahuhopu i loko o ka wai. ʻO nā pulse Femtosecond (800 nm, 100 fs, 500 μJ, 1 kHz) i hana ʻia e kahi amplifier regenerative laser Ti:sapphire e kālele ʻia e kahi lens a hoʻomālamalama pololei ʻia ma luna o ka ʻili silicon (hoʻokele ʻia ka ikehu hoʻopuka laser e kahi attenuator, nona ka pā hapalua nalu a me kahi polarizer). Ma ka neʻe ʻana i ke kahua pahuhopu e scan i ka ʻili silicon me ka wahi laser, hiki ke loaʻa kahi mea silicon ʻeleʻele nui. ʻO ka hoʻololi ʻana i ka mamao ma waena o ka lens a me ka wafer silicon hiki ke hoʻoponopono i ka nui o ke kiko kukui i hoʻomālamalama ʻia ma ka ʻili silicon, a laila e hoʻololi ana i ka fluence laser; ke paʻa ka nui o ke kiko, ʻo ka hoʻololi ʻana i ka wikiwiki o ka neʻe ʻana o ke kahua pahuhopu hiki ke hoʻoponopono i ka helu o nā pulse i hoʻomālamalama ʻia ma kahi ʻāpana o ka ʻili silicon. Hoʻopilikia nui ke kinoea hana i ke ʻano o ka microstructure ʻili silicon. Ke paʻa ka kinoea hana, ʻo ka hoʻololi ʻana i ka fluence laser a me ka helu o nā pulse i loaʻa i kēlā me kēia ʻāpana hiki ke hoʻomalu i ke kiʻekiʻe, ka lakio hiʻohiʻona, a me ka mamao o nā microstructures.
1.2 Nā ʻano Microscopic
Ma hope o ka hoʻomālamalama ʻana o ka laser femtosecond, hōʻike ka ʻili silicon crystalline laumania mua i kahi ʻano o nā ʻano conical liʻiliʻi i hoʻonohonoho pono ʻia. Aia nā piko cone ma ka mokulele like me ka ʻili silicon i hoʻopuni ʻole ʻia. Pili ke ʻano o ke ʻano conical i ke kinoea hana, e like me ka mea i hōʻike ʻia ma ke Kiʻi 2, kahi i hoʻokumu ʻia ai nā ʻano conical i hōʻike ʻia ma (a), (b), a me (c) i nā lewa SF₆, S, a me N₂. Eia nō naʻe, kūʻokoʻa ke kuhikuhi o nā piko cone mai ke kinoea a kuhikuhi mau i ke kuhikuhi o ka hanana laser, me ka hoʻopilikia ʻole ʻia e ka umekaumaha, a kūʻokoʻa hoʻi i ke ʻano doping, resistivity, a me ke kuhikuhi kristal o ka silicon crystalline; ʻaʻohe like nā kumu cone, me ko lākou axis pōkole e like me ke kuhikuhi polarization laser. ʻO nā ʻano conical i hoʻokumu ʻia i ka lewa ka mea ʻoi loa ka ʻino, a ua uhi ʻia ko lākou mau ʻili me nā nanostructures dendritic maikaʻi loa o 10-100 nm.
ʻO ke kiʻekiʻe o ka fluence laser a me ka nui o ka helu o nā pulse, ʻo ke kiʻekiʻe a me ka laulā o nā ʻano conical. I loko o ke kinoea SF6, ʻo ke kiʻekiʻe h a me ka spacing d o nā ʻano conical he pilina nonlinear, hiki ke hōʻike ʻia ma ke ʻano he h∝dp, kahi p=2.4±0.1; piʻi nui ke kiʻekiʻe h a me ka spacing d me ka hoʻonui ʻana o ka fluence laser. Ke piʻi ka fluence mai 5 kJ/m² a i 10 kJ/m², piʻi ka spacing d i 3 mau manawa, a i hui pū ʻia me ka pilina ma waena o h a me d, piʻi ke kiʻekiʻe h i 12 mau manawa.
Ma hope o ka hoʻomehana wela kiʻekiʻe (1200 K, 3 h) i loko o kahi vacuum, nā ʻano conical osilika ʻeleʻeleʻaʻole i loli nui, akā ua hoʻemi nui ʻia nā nanostructures dendritic 10-100 nm ma luna o ka ʻili. Ua hōʻike ka spectroscopy channeling Ion ua emi ka haunaele ma ka ʻili conical ma hope o ka annealing, akā ʻaʻole i loli ka hapa nui o nā ʻano hana ʻole ma lalo o kēia mau kūlana annealing.
1.3 ʻAno Hoʻokumu
I kēia manawa, ʻaʻole maopopo ke ʻano hana o ka silicon ʻeleʻele. Eia nō naʻe, ua kuhi ʻo Eric Mazur et al., ma muli o ka loli o ke ʻano o ka microstructure o ka ʻili silicon me ka lewa hana, ma lalo o ka hoʻoulu ʻia ʻana o nā lasers femtosecond kiʻekiʻe, aia kahi hopena kemika ma waena o ke kinoea a me ka ʻili silicon crystalline, e ʻae ana i ka ʻili silicon e kahakaha ʻia e kekahi mau kinoea, e hana ana i nā cones ʻoi. Ua hoʻopili ʻo Eric Mazur et al. i nā ʻano hana kino a me ke kemika o ka hoʻokumu ʻana o ka microstructure o ka ʻili silicon i: ka hoʻoheheʻe ʻana a me ka ablation o ka substrate silicon i hoʻokumu ʻia e nā pulse laser fluence kiʻekiʻe; ka etching o ka substrate silicon e nā ion reactive a me nā ʻāpana i hana ʻia e ke kahua laser ikaika; a me ka recrystallization o ka ʻāpana ablated o ka substrate silicon.
Hoʻokumu koke ʻia nā ʻano conical ma luna o ka ʻili silicon, a hiki ke hoʻokumu ʻia kahi ʻano quasi-regular me ka ʻole o kahi mask. Ua hoʻopili ʻo MY Shen et al. i kahi ʻupena keleawe microscope electron transmission 2 μm mānoanoa i ka ʻili silicon ma ke ʻano he mask, a laila hoʻomālamalama i ka wafer silicon i loko o ke kinoea SF6 me kahi laser femtosecond. Ua loaʻa iā lākou kahi ʻano hoʻonohonoho maʻamau o nā ʻano conical ma luna o ka ʻili silicon, e kūlike me ke ʻano mask (e nānā i ke Kiʻi 4). Hoʻopilikia nui ka nui o ka puka o ka mask i ka hoʻonohonoho ʻana o nā ʻano conical. ʻO ka diffraction o ka laser incident e nā puka mask ke kumu o ka hoʻolaha like ʻole o ka ikehu laser ma luna o ka ʻili silicon, e hopena ana i ka hoʻolaha mahana periodic ma luna o ka ʻili silicon. ʻO kēia ka mea hope loa e koi ai i ka ʻano hoʻonohonoho ʻili silicon e lilo i maʻamau.