高性價(jià)比顆粒硅帶多晶硅薄膜電池

1、no瓜抵生長(zhǎng)展Ti/FiAs咼性價(jià)比顆粒硅帶多晶硅溥膜電池1.摘要運(yùn)用SSP及RTCV技術(shù)，制備以顆粒硅帶為襯底的多晶硅薄膜電池。該電池具有相對(duì)較 效率，但成本也相對(duì)低廉。襯底上外延生長(zhǎng)高純硅來制作高性價(jià)比的多晶硅薄膜電池。我們用廉價(jià)的冶金級(jí)硅粉在顆粒硅帶儀器（ 。然而如果在這種硅片表面沉積一層高純硅，然后再在上面做電池，則既保證了效率又大大降低了成本。SSF）上拉制硅帶，如果直接用其來制造電池，必然SSP襯底多晶硅薄膜電池的截面結(jié)構(gòu)如圖1所示薄膜電池研究上，人們正致力于兩個(gè)方向的研究：其一是提高光伏轉(zhuǎn)換效率；另一是降低成本。正是基于這樣的考慮，我們與德國(guó)Fraunhofer 研究所合作P為襯

2、底的多晶硅薄膜太陽(yáng)電池基本結(jié)構(gòu)示意圖摻硼的P型SSP襯底。以廉價(jià)的低純度硅粉為原料，通過改變加熱源的輸岀功率改變顆粒硅帶成型過程中的熱場(chǎng)配置，制備岀SSP襯底材料。硅粉粒度在調(diào)），晶體生長(zhǎng)速度為30mm/min （可調(diào)）。制得的 SSPi式片厚度和表面薄層電阻率分別約為1000um和1 Q .cm。片為襯底在RTCV設(shè)備上外延一層高純硅。 RTCV設(shè)備的工作原理如圖所示。外延鍍膜實(shí)驗(yàn)先在超凈室內(nèi)對(duì)襯底基片稱重，然后將10片10X 10cm2的襯底右）推入石英反應(yīng)管（直徑160mm，開始反應(yīng)。反應(yīng)后取出襯底片稱量。 RTCVD升溫速度快，采用低成本的 SiHCI3生長(zhǎng)源，并可在短時(shí)間內(nèi)（10mi

3、n） 直 的、膜層較厚的多晶硅薄膜。RTCVD法生長(zhǎng)摻硼多晶硅薄膜的工藝參數(shù)為：生長(zhǎng)源 SiHCI3的流量為10g/min，p型摻雜劑B2H6的流量為2SCCM載氣H 長(zhǎng)溫度為11001200° C,升溫速率為100-200 °C /min，生長(zhǎng)速率為2-4mm/min，整個(gè)反應(yīng)在常壓下進(jìn)行。exhaustprocess halogen lamps inner volume制備該電池的工藝流程為：SSP?寸底清洗？襯底表面預(yù)處理?RTCVD生長(zhǎng)多晶 硅薄膜？擴(kuò)散制結(jié)？掩膜法制作上下電極？去邊？測(cè)試。結(jié)果與討論粒硅帶晶相結(jié)構(gòu)分析 ，用低純度硅粉加工制備的SSP襯底表面晶面具有

4、擇優(yōu)性（圖 3、4）圖3 MEMC硅粉為原料的硅帶的 XRD圖硅粉為原料的硅帶的XRD圖MM ：1 MIHMI - f-. |! *f* F “屮一盧II X KI I 旦耳電阻率約為硅薄膜表面形態(tài)及晶相結(jié)構(gòu)分析SEM分析（見圖3）表明，在SSP襯底上生長(zhǎng)的多晶硅薄膜晶粒為定向排列的大直徑的柱狀體，晶粒大小為幾個(gè)微米，薄膜厚度約40卩射XRD譜表明（圖4）,晶向主要為220，與一般薄膜生長(zhǎng)中110成為優(yōu)選晶向一致。以看岀，薄膜晶粒為定向排列的大直徑的柱狀體，因而整個(gè)電池就相當(dāng)于由若干個(gè)小柱狀的單晶電池并聯(lián)而成，這將有利于提高太陽(yáng)電池的效率。池性能襯底的多晶硅薄膜的太陽(yáng)電池的性能參數(shù)見表1硅薄膜

5、太陽(yáng)電池的性能參數(shù)Voc mVJSC mA/cm2FF11 ( x 10-13 mA/cm2)12( x 10-9 mA/cm2)n %370.516.780.554186000645003.4正棗址背電祗TiFF"幅LOWCOSTPOLYCRYSTALLINE THIN FILM SOLAFCELLSWITHSI SAS SUBSTRATE1. ABSTRACTBy using SSP (Sheets from Si powder) and RTCVD(Rapid Thermal Chemical VapoDeposition)technology, polycrystalline

6、 Si thin film solar cells were fabriII shows relatively low conversion efficiency, but involves a low cost.RODUCTION ow,in the field of the crystalline Si solar cells there are still two important topics to develop: the first is to increase photovoltaic con ency; the second is to decrease production

7、 costs. Based on this, we currently cooperate with Fraunhofer institute for solar energy sys search of poly-Si thin film solar cells with SSP as substrate. We made silicon ribbon from inexpensive low-purity industrial silicon p otovoltaic conversion efficiencies cannot be expected when processing it

8、 to solar cells due to its high impurity content. However, this sit improved when depositing a thin pure silicon layer epitaxially on the top of the ribbon, so we got low cost but relatively high efficiencThe structure of solar cell is shown as Fig.1.The structure of polycrystalline Si thin film sol

9、ar cells on SSP substrateERIMENTALng B2H6 as precursor gases, we got P type SSP substrate. The particle dimension of silicon powder is in the range of 50-1000卩 m The thiectric resistance of the SSP substrate are 1000um and1Q .cm.:Scheme of the deposition process of the CVD system.pure silicon layer

10、was epitaxially deposited on the top of the SSP substrate by using RTCVD instrument. The work principle of RTCVD is.2. Firstly, the weights of SSP substrates were measured on a electronic balance in a clean room, then ten pieces of 10x 10cm2 substrateorted into a quartz tube(160mm in diameter), and

11、then a computer program were set to run. Finally, the substrates were taken out and me when the deposition was over. RTCVD machine has rapid speed for heating, and low cost SiHCl3 was used as reaction gas. The polycrystalllm can be made in a very short time(about 10 minutes). The experimental parame

12、ter of polycrystalline Si thin film are shown as follows:Th ction gas SiHCl3 is 10g/min, the flux of precursor gases B2H6 and H2 are respectively 2sccm and 7slm. Reaction temperature is 1100 tion speed is 2-4mm/min, the whole reaction is under standard pressure(1 atm.).precesshalogen lamps inner vol

13、umeuwuwuuexbiduftThe manufacture sequence of solar cells' fabrication technologyis: SSP?cleaning the substrates? pretreatment on the substrates /deposition by RTCVD instrument?diffusion process?making electrode ?removing the edges?testing.SiHC, + H.ULT AND DISCUSSION aracterization of SSPFigure

14、3 XRD diagram of ssp from MEMCFig.4 XRD diagram of ssp from industrial powdersults of X-Ray diffraction analysis of SSP(Fig.3,4) indicate that the grains exhibit preferred growth orientation.aracterization of Polycrystalline Si Thin Filmsult of the Scanning Electron Microscope(SEM) (Fig.5) shows tha

15、t the polycrystalline Si thin film is well crystallized, the particlesof X-Ray diffrgrowth orientension of micron meter, the thickness of the film is about40 micron. The electric resistance is about 0.05 Q cm. The resultsis(Fig.6) indicate that the grains exhibit preferred growth orientation Si (220), which is in coincide with Si film ' s preferredSEM image of a cross section of the polycrystalline Si thin film rformance of Solar Cellrformance parameters of the solar cell fabr