Photovotaics ndi chiyani?

Chithunzi pamwambapa chikuwonetsa kagwiridwe kake ka cell photovoltaic cell, yotchedwanso solar cell. Maselo a dzuwa amapangidwa ndi mitundu yofanana ya zida za semiconductor, monga silicon, zomwe zimagwiritsidwa ntchito pamakampani opanga ma microelectronics. Kwa ma cell a dzuwa, chowotcha chopyapyala chochepa kwambiri cha semiconductor chimapangidwa mwapadera kuti chipange gawo lamagetsi, labwino mbali imodzi ndi loyipa mbali inayo. Mphamvu ya kuwala ikagunda cell solar, ma elekitironi amachotsedwa ku ma atomu omwe ali mu semiconductor material. Ngati ma kondakitala amagetsi amangiriridwa ku mbali zabwino ndi zoipa, kupanga dera lamagetsi, ma elekitironi amatha kugwidwa ngati mphamvu yamagetsi -- ndiye kuti, magetsi. Magetsi amenewa atha kugwiritsidwa ntchito kupatsa mphamvu katundu, monga nyali kapena chida.

Maselo angapo a dzuwa olumikizidwa ndi magetsi wina ndi mnzake ndikuyikidwa munjira yothandizira kapena chimango amatchedwa photovoltaic module. Ma module amapangidwa kuti azipereka magetsi pamagetsi ena, monga ma volts 12 wamba. Zomwe zimapangidwira zimadalira mwachindunji kuchuluka kwa kuwala komwe kumakhudza module.

Zipangizo zamakono zamakono za PV zimagwiritsa ntchito mphambano imodzi, kapena mawonekedwe, kuti apange gawo lamagetsi mkati mwa semiconductor monga PV cell. Mu cell-junction PV cell, ma photons okha omwe mphamvu zawo ndi zofanana kapena zazikulu kuposa kusiyana kwa gulu la cell zomwe zimatha kumasula electron pamagetsi amagetsi. Mwa kuyankhula kwina, kuyankhidwa kwa photovoltaic kwa maselo amtundu umodzi kumangokhala ku gawo la kuwala kwa dzuwa komwe mphamvu yake ili pamwamba pa gulu la zinthu zomwe zimayamwa, ndipo ma photon otsika kwambiri sagwiritsidwa ntchito.

Njira imodzi yochepetsera malirewa ndikugwiritsa ntchito ma cell awiri (kapena kupitilira apo) osiyanasiyana, okhala ndi mipata yopitilira gulu limodzi ndi maphatikizidwe opitilira amodzi, kuti apange magetsi. Awa amatchedwa ma cell a "multijunction" (omwe amatchedwanso "cascade" kapena "tandem" cell). Zipangizo za Multijunction zimatha kukwanitsa kutembenuka kwakukulu chifukwa zimatha kutembenuza mphamvu zambiri zamagetsi kukhala magetsi.

Monga momwe tawonetsera pansipa, chipangizo chophatikizirapo ndi mulu wa maselo amtundu umodzi womwe umatsikirapo wa kusiyana kwa band (Mwachitsanzo). Selo lapamwamba limagwira ma photon amphamvu kwambiri ndikudutsa ma photon ena onse kuti atengedwe ndi maselo apansi a band-gap.