Abstract
Thepaperdescribesthewaytotransferprocesstechnologyofstate-of-the-arthighefficiencythinfilm siliconsolarcellsfabricationoncheapplastic(suchasPETorPEN)substrates,bytwocompletelydifferent approaches:(i)bytransferprocess(Helianthosconcept)ofthinfilmsiliconcellsdepositedathigh substratetemperature, Ts ( 200 1C) and(ii)directdepositionontemperaturesensitivesubstratesatlow Ts ( 100 1C).Adaptationoftheprocessparametersandcellprocessingtotherequirementoftheflexible/ plasticsubstrateisthemostcrucialstep.In-situdiagnosisoftheplasmahasbeendonetounderstandthe effectofinter-electrodedistance,substratetemperatureandhydrogendilutiononthegasphase conditions.Whereas,forthetransferprocess,theinter-electrodedistanceisacriticaldepositioncondition thatneedstobeadaptedfortheflexiblesubstrates,thedirectdepositiononplasticsubstrateshasan addedissueoflossinmaterialqualityandthedepositionrateduetodepositionsatlow Ts. Ourstudies indicatethationenergyiscrucialforobtainingcompactfilmsatlowtemperatureandhighhydrogen dilutionhelpstocompensatethelossofionenergyatlowsubstratetemperatures.Efficienciesof 5.9% and6.2%havebeenobtainedforn–i–ptypea-SicellsonPETandPENsubstrates,respectively,usingdirect deposition.Usinganadaptedinter-electrodedistance,ana-Si/nc-Sitandemcellonplastic(polyester) substratewithanefficiencyof8.1%hasbeenmadebyHelianthoscelltransferprocess.