高性价比颗粒硅带多晶硅薄膜电池

1、no瓜抵生长展Ti/FiAs咼性价比颗粒硅带多晶硅溥膜电池1.摘要运用SSP及RTCV技术，制备以颗粒硅带为衬底的多晶硅薄膜电池。该电池具有相对较 效率，但成本也相对低廉。衬底上外延生长高纯硅来制作高性价比的多晶硅薄膜电池。我们用廉价的冶金级硅粉在颗粒硅带仪器（ 。然而如果在这种硅片表面沉积一层高纯硅，然后再在上面做电池，则既保证了效率又大大降低了成本。SSF）上拉制硅带，如果直接用其来制造电池，必然SSP衬底多晶硅薄膜电池的截面结构如图1所示薄膜电池研究上，人们正致力于两个方向的研究：其一是提高光伏转换效率；另一是降低成本。正是基于这样的考虑，我们与德国Fraunhofer 研究所合作P为衬

2、底的多晶硅薄膜太阳电池基本结构示意图掺硼的P型SSP衬底。以廉价的低纯度硅粉为原料，通过改变加热源的输岀功率改变颗粒硅带成型过程中的热场配置，制备岀SSP衬底材料。硅粉粒度在调），晶体生长速度为30mm/min （可调）。制得的 SSPi式片厚度和表面薄层电阻率分别约为1000um和1 Q .cm。片为衬底在RTCV设备上外延一层高纯硅。 RTCV设备的工作原理如图所示。外延镀膜实验先在超净室内对衬底基片称重，然后将10片10X 10cm2的衬底右）推入石英反应管（直径160mm，开始反应。反应后取出衬底片称量。 RTCVD升温速度快，采用低成本的 SiHCI3生长源，并可在短时间内（10mi

3、n） 直 的、膜层较厚的多晶硅薄膜。RTCVD法生长掺硼多晶硅薄膜的工艺参数为：生长源 SiHCI3的流量为10g/min，p型掺杂剂B2H6的流量为2SCCM载气H 长温度为11001200° C,升温速率为100-200 °C /min，生长速率为2-4mm/min，整个反应在常压下进行。exhaustprocess halogen lamps inner volume制备该电池的工艺流程为：SSP?寸底清洗？衬底表面预处理?RTCVD生长多晶 硅薄膜？扩散制结？掩膜法制作上下电极？去边？测试。结果与讨论粒硅带晶相结构分析 ，用低纯度硅粉加工制备的SSP衬底表面晶面具有

4、择优性（图 3、4）图3 MEMC硅粉为原料的硅带的 XRD图硅粉为原料的硅带的XRD图MM ：1 MIHMI - f-. |! *f* F “屮一卢II X KI I 旦耳电阻率约为硅薄膜表面形态及晶相结构分析SEM分析（见图3）表明，在SSP衬底上生长的多晶硅薄膜晶粒为定向排列的大直径的柱状体，晶粒大小为几个微米，薄膜厚度约40卩射XRD谱表明（图4）,晶向主要为220，与一般薄膜生长中110成为优选晶向一致。以看岀，薄膜晶粒为定向排列的大直径的柱状体，因而整个电池就相当于由若干个小柱状的单晶电池并联而成，这将有利于提高太阳电池的效率。池性能衬底的多晶硅薄膜的太阳电池的性能参数见表1硅薄膜

5、太阳电池的性能参数Voc mVJSC mA/cm2FF11 ( x 10-13 mA/cm2)12( x 10-9 mA/cm2)n %370.516.780.554186000645003.4正枣址背电祗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