薄膜太阳能电池中半导体电极热电性质的第一性原理-.研究

《薄膜太阳能电池中半导体电极热电性质的第一性原理-.研究》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、坝lj学位论文AbstractIn203isoneofthetypicalTransparentConductiveOxides(TCOs)．Sinceithasboththehighelectricconductanceandthevisiblelighttransmissibility，itispopularlyusedinthethinfilmsolarcellastransparentelectrode．P．ZnTeisusuallybeenusedastransitionelectrodetocutdowntheelectr

2、icpotentialofthebackcontactmetalelectrode．Pb025Zno75Teternaryalloy--oneoftheR(Sn，Pb)xZn(一x)Tealloys—isthenewalloycompoundthatcanusedasanewsolarcellbackcontacteletrodeviaformingheterojunctionwithp—ZnTe--Whatwestudyinthisthesiswerebasedonthesetwosemiconductorelectrodesmat

3、erials．AlthoughresearchesontheIn203areabundant，thenatureofthebandgapinthematerialremainscontentious．Usingthefirstprinciplestheorywe’vecalculatedthebandstructureandopticalpropertiesoftheIn203bulkmaterial，anddemonstratedthattheIn203bulkmaterialisadirectgapoxide．Becauseoft

4、heLaporteselectiveruleonthequantumtransition，thetransitionfromtheVBMtotheCBMofriSforbbiden．Itisonlyfromo．7eVbelowtheVBMthatthestrongtransitionsareobserved．Withtherelativelyhighcarriermobility，In203isconsideredtobeoneofthegoodthermoelectricmaterialswithhighZTfactor．We’ve

5、calculatedthethermoelectricpropertiesofIn203asfunctionofcarrierconcentrationattheroomtemperatureandthethermoelectricpropertiesasfunctionofthetemperature．Wefoundthatattheroomtemperature，inthep—typeconductionmechanismthereexistarelativelyhighthermalefficiencyunderhighconc

6、entrationarea．andinthen—typeconductionmechanism，thefigureofmeritunderlowconcentrationrangewillbegreaterthantheonesoverthehighconcentrationrange．Thepowerfactorandelectricalthermalconductivitybecomelargerasthetemperaturegetshigher．Basedonthefirstprinciplesstudyandthesemi-

7、classicalBoltzmanntransporttheory，we’vecalculatedthefigureofmeritZTatdifferentcarrierconcentrationsunderboththen—andp-typeconductionmechanism．Ingeneral，theZTsoftheR(Sn，Pb)ZnTeternaryalloysaresmallerthanthepureZnTebulk，andthethermoelectricpropertyundertheP—typeconduction

8、mechanismisbetterthanthen—conductionmechanismmostly．Inthep—typeconductionmechanism，theZTsbecomesmallerastheRco