太阳能电池论文

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3、 weloff sc* ad pr omotng Ie al r oud . elpmet of peopl es perorma ci eet lat a-mplsmes, a_ ai ote lok at the fec ne- of sea pr ogress Ca es baand rural can” bot had e nvionme nt tsregt he a nd another l ook at the si evionmet imprlament momentof . l opme nt a present, de pedng onte poteta for sustai

4、 nabl e . lopme nt Lea- people t、. a boutare wrts and peope t oak about "Oul ook" s not watt he pefrma nce.4p.p. rmonne d to the sarig poit of te queston, ad rele d t qust ons point Ma n s the sm ofsociare atonshi ps W ca I not lev e te chchua nyngdu, hous ng.tulsm ad eeranmet, e nertini n

5、g ad eve ceai polt cal e cnomic cul ual ad scil e nvronme nt and s on. IDe t luma n nee is, al aB of ie lcmeito be ng Pepe crae fr thei -.iva,a nd cont nneen. m g tereu-of tecnnt uclon. Ccloru i t hetansormaton of tepepe of te -orl d,cmmuni，vitaiS i the ceai on ofma.Theeore , an, . e do, the sat ng

6、poit s huma, -ha ae pepe. Us seld u dewlpment, tece of -hi c s t o m-tthe nees if pe ople includig -viva nee dsemot ona lnne ds and -l-tal-t needs. It so. d be note d that pe opl e ae not maci nes not te saw of a objel, not t becnt.- d. Pe opl e ha - thei o- pesnaiy has is o n pesnal ，ha s is o - di

7、g niy Pesn i I >e d of cae， ounnedto unndesad neldtmee. I s .ad t ha in the、-ulua socie， peple pl ant" i、.s.l .ce，ma n s a a nimar, "he iforma1nsce，-eu.：2012-2013学年第 二学期 物电学院期末考试卷I物理前沿讲座II；学号:7 姓名：陈永泽 班级：10级物理3班III4;成绩：II:评语：（考试题目及要求）s one ofthe”ccl fomof vale sThe so dids rees tie obje

8、cve li ngs ae of novaue ad Ie vale of un.ea pespecve. Dfeet vaues, peoples be. a>， s,ways dHent. Pepeo_nted fcus onh - ava a. rea , nee. the br .aies masses as vale s Adee to e opeorbetid* s "mate Ie ecnomy more developme nt, mpove d i .a . cut ua pros” y, ad - ahapi er s deey conce nei t ha

9、 huma nveipment a. h - ava* deve opme nt of sc, a nd h a atonal uniid, ins_bd in the maerai Cvl .i cHIzai on a nd spiiua cvizat oveal a n.-et i f Sealst civonta hgher level Asowant tosee that person's vaue .ee you nee , aso is tomee Ienee - ad the cmmuiy Adee topeopeoriee、tostongy aive everycomm

10、uh member,serve othes, be-i al tie commu niy of peopl. T he sc d Oul ook ide s on there crd, inc - ig w toate a recd of aci ments how taupefrmace aI d son. Wa es wa kid of Outlook hee topeope ore ntd lok, s ontheprrmie of respeci ng the i nteess ad po-weof peI pl e ceat ng a popul a, mhe ats, sedy h

11、eat pefrmanneceaig、ve fr one olice, the be nei -" icheets, ado<eal cnstrcton of weloff sc* ad promoig Ie alr oud develpmet of peoples pefrmanne-cievmet -lat a ccmplsmets, take aI othe 10k at the feciene- of scil pr ogrss ca baand rua can” both had e nvrnme nt tsregt he a nd tae aothe l 00k a

12、t the si evio nment mpr lament momet-of d l opme nt a preent, de pedig onthe poteta forlusanal e d lopment LLa<epepe tolakboutae wrthlss and <e peope t o tak abou "Oulook" snot wat the pefrma nne.4. pepe resonne d to the sarig poit ofte _esin, ad re- d t qust ons point Ma ns the sm o

13、fsocilre ainshi ps W ca I not lev e te chchua nyngdu, housng,tu - m ad eeranmet, enertii ng ad eve ceai polt cal e cnomic cul ual ad scil e nvionme nt and s on. IDe t luma n nee is, al w als of ie wl cme ito be ng Pepe crae fr theiluviva,and cont nneen.oig tereulsof tecnntr ucton. Ccloru i t he tans

14、ormain of tepepe of te worl d,cmmuniyviaiy i the ceai onof ma. Thereore, any wkwe do, the sat ng poit s huma, wha ae pepe. Us seldu deelpment,tece of whic s t o mletthe nees if people includigluviva nee dsemot ona lnne ds and latalzt needs. It sou d be note d that pe opl e ae not maci nes not te sae

15、 of a objec, not t becnt.- d. Pe opl e ha - thei ow pesnaiy, has is ow n pesnal iy,ha s is ow dg nity Pesn i I>ed of cae y ounnedto unndesadneld1mee. I s .ad t ha in the、-ulua sociey peple pl ant" i i_s_l scey .a n s a a"" "he if0rmi11nsciey, reu.太阳能电池原理及发展摘要：人类面临着有限常规能源和环境破坏严

16、重的双重压力，己经 成为越来越值得关注的社会与环境问题。 近年来，光伏市场快速发展 并取得可喜的成就。本文介绍了太阳能电池的原理和发展，以及各类 新型太阳能电池，比较了各类太阳能电池的转换效率和发展前景。 关键字：太阳能电池；原理；发展；前景1 .引言由于人类对可再生能源的不断需求，促使人们致力于开发新型能源。太阳在 40min内 照射到地球表面的能量可供全球目前能源消费的速度使用1年，合理的利用好太阳能将是人类解决能源问题的长期发展战略，是其中最受瞩目的研究热点之一。 本文介绍了太阳能电池的原理和发展，以及各类新型太阳能电池，比较了各类太阳能电池的转换效率和发展前 景。2 .太阳能电池原理太

17、阳能电池，是一种能有效地吸收太阳辐射能，并使之转变成电能的半导体器件，由于他们利用各种势垒的光生伏特效应，所以也称为光伏电池，其核心是可释放电子的半导体。 最常用的半导体材料是硅。地壳硅储量丰富，可以说是取之不尽、用之不竭。当太阳光照射到半导体表面，半导体内部N区和P区中原子的价电子受到太阳光子的激发，通过光辐射获取到超过禁带宽度 Eg的能量，脱离共价健的束缚从价带激 发到导带，由此在半导体材料内部产生 出很多处于非平衡状态的电子空穴对。 这些被光激发的电子和空穴，或自由碰 撞，或在半导体中复合恢复到平衡状态。 其中复合过程对外不呈现导电作用，属 于太阳能电池能量自动损耗部分。光激 发载流子中

18、的少数载流子能运动到P N结区，通过 P- N结对少数载流子的牵 引作用而漂移到对方区域，对外形成与 P N结势垒电场方向相反的光生电场。 一旦接通外电路，即可有电能输出。当阴极基彳卜抗反射涂层 二前接触面发发层阳极F?接触面图I太阳能电池工作原理把众多这样小的太阳能光伏电池单元通过串并联的方式组合在一起，构成光伏电池组件， 便anda nd manpower devel opme nt,and seeking,majorproblemaemand foster advais one ofthepra cticalformofvalue s.Theso-calledval uesrefers

19、tothe objective thi ngs are ofnovalueand thevalue offundamentalperspective.Differentvalues, people's behaviour, attitudes,ways aredifferent.People-orientedfocusonhuman value and reality,weneedthe br oade stmassesasvalue s.A dhereto pe ople -oriented val ues, ist omakethe economymoredevelopme nt,

20、improve democracy, cult uralprosperit y,and live a happi er;is deeply concer nedt hat huma n deve lopme ntand humanvalue s, devel opme nt of social a ndhuman developmentofrationalunified,insisted i nthe materialcivili zation,political civilizati on a ndspiritual civilizati on i nthe ov eralladvancem

21、ent ofSociali st civilizati on toa higher level.Alsowant tosee that person's value isnotonly meetyour needs,also istomeetthenee ds ofot hers andthe community.A dheret ope ople -or iented,to stronglyadvocateeverycommunitymember,serveothers,benefici altothe communityofpeople.T heso-calle d Outl oo

22、kattitude is onthe re cord, includingw ho, howto create arecordofachievements,howtoevaluateperformance, a nd so on.What values,what kindofOutlook.Adheretopeople-orie ntedOutlook,is on thepremiseofrespecti ng the i nterestsand powerofpeople,creati ng a popul ar,warmhe arts,steady heart performance,cr

23、eating"servefor one officer,the be nefitof"achievement s,and overallconstruction ofwell-offsociety and pr omoting theall-r ound developmentof peopl e's performa nce.Achi evement evaluati on i n bot heconomic a ccomplishments,take anotherlookattheeffectivenessofsocialpr ogress; cha nges

24、 in bot h ur ban a nd rural change; both harde nvironme nttostrengt hen a ndtake an otherl ook atthe softenvironmentimprovementmomentumofdevel opme ntat present, de pending onthe potentialforsustai nabl edevel opme nt. Leave people totalka bout"values"are worthlessand leave peoplet otalkab

25、out "Outl ook" is notwhatt heperforma nce.4. peopleresponde dtothe startingpoint ofthequestion,andreplied toquesti ons poi nt. Ma n isthe sumofsocial rel ationshi ps. Weca nnot leav ethe chichua nyongdu,housi ng,tourism andentertainment,e ntertaini ng,andeven certain politi cal,e conomic,c

26、ult uraland sociale nvironme nt, andso on. Due to huma n nee ds,allw alksoflifewillcomeintobei ng. People create fortheir survival,a nd conti nueenjoying theresultsoftheconstruction. Colrfulin t hetransformation ofthepeople oftheworl d,communityvitality in thecreation of man.Therefore , anywork wedo

27、, thestarti ng pointis human,whatare people.Us speed up development,thecore ofwhi chis t o meetthe needs ofpe ople, incl udi ng survivalnee ds,emoti ona lnee ds and se -actualizationne eds.It shoul d be note dthatpe opl e arenot machi nes, notthe slave ofan object, nottobecontrolle d.Pe opl e haveth

28、eir own personality,hasits ow n personal ity,has its owndig nity. Person in nee d ofcare,y ou needto understand, needtomeet.Itis saidt hat inthe "agriculturalsociety, peoplepl ant" in"industrial society, ma n isana nimal""the information society,return会在太阳能的作用下输出功率足够大的电能。制造太

29、阳能电池的半导体材料有合适禁带宽度非常重要。不同禁带宽度的半导体，只能吸取一部分波长的太阳光辐射能以产生电子空穴对，禁带宽度越小，所吸收的太阳光谱的可利用部分就越大，而同时在太阳光谱峰值附近被浪费的能量也就越大。可见， 只有选择具有合适禁带宽度的半导体材料，才能更有效地利用太阳光谱。由于直接迁移型半导体的光吸收效率比间接迁移型高，故最好是直接迁移型半导体。3. 太阳能电池的发展3.1 . 第一代太阳能电池1954 年，美国贝尔实验室研制出第一块半导体太阳能电池，开始了利用太阳能发电的新纪元。由于太阳能电池价格昂贵，因此其发展缓慢，当时主要用于航天科技工程。20 世纪 70 年代，由于石油危机，

30、使人们对于可再生能源的兴趣越来越浓，太阳能电池也进入了快速发展的阶段。近几年太阳电池市场以每年30%的速度递增。目前，第一代太阳能电池约占太阳能电池产品市场的86% 。第一代太阳能电池基于硅晶片基础之上，主要采用单晶体硅、多晶体硅及 GaAs为材料，转换效率为11%15%单晶硅生长技术主要有直拉法和悬浮区熔法。直拉法是将硅材料在石英坩锅中加热熔化，使籽晶与硅液面接触，向上提升以长出柱状的晶棒。直拉法的研究方向是设法增大硅棒的直径（目前硅棒的直径已经达到100150mm） ，用区熔法生长单晶硅技术是将区熔提纯和制备单晶结合在一起，可以得到纯度很高的单晶硅，但成本很高。目前，在所有太阳能电池中此种

31、硅片的效率是最高的，因此， 采用低成本的方式改进区熔法生长太阳能电池用单晶硅也是目前的发展方向。为了进一步提高太阳能电池效率，近年来大力发展高效化电池工艺，主要有发射极钝化及背面局部扩散工艺、埋栅工艺和双层减反射膜工艺等。多晶硅材料生长主要运用定向凝固法及浇铸法工艺。定向凝固法是将硅材料在坩锅中熔融后，使坩锅形成由上而下逐渐下降的温度场或从坩锅底部通冷源以造成温度梯度，使固液界面从坩锅底部向上移动而形成晶体。浇铸法是将熔化后的硅液倒入模具内形成晶锭，铸出的方形硅锭被切成方形硅片做成太阳电池。目前使用最广泛的是浇铸法，此法简单，能耗低， 利于降低成本，但容易造成错位、杂质等缺陷，而导致光电转换效

32、率低于单晶硅太阳能电池。由于多晶硅太阳电池存在杂质问题，光电转换效率比单晶硅电池低但成本有所降低。目前阻碍太阳能电池推广应用的最大障碍就是成本问题，为进一步降低成本，基于薄膜技术的第二代太阳能电池登上了历史舞台。【 2】3.2 第二代太阳能电池第二代太阳能电池是基于薄膜技术之上的一种太阳能电池。在薄膜电池中，很薄的光电材料被铺在衬底上，大大地减小了半导体材料的消耗（薄膜厚度仅1um） ，也容易形成批量生产（其单元面积为第一代太阳电池单元面积的100 倍） ，从而大大地降低了太阳能电池的成本。 薄膜太阳能电池材料主要有多晶硅、非晶硅、碲化镉等。多晶硅薄膜太阳能电池技术较为成熟。ow,w e ar

33、ein apoliticalparticipatiquality ofyourprenew hi stori calstageof allon ba sed on conspir acy to a-roundconstructionofa wellsentati on,mai nlydepends onhow much wedhereto pe opl e-oriente-offsociety.drafteda documentred,will bearoundto pr omotecoor dinationDevelopmentevecog nize dbythe le adership,

34、howmanyare listents,great searchings.Theport, howmanyce modifiednotdogn-dept hdograndstah thindi ng ofcosmetic,toseeki ngofstyle,helpmassesshare,iselopment haestee people is notonly an is be come theparty's importantwdea,itis ajob requireme nt.Philosophythrougto the people -oor ientedt houg ht i

35、nthe work ofthe Office, must beclearworkobjectives. PartyOfficeinthe citythisyearremains:A dvancedcivilstrife, localbrand.The County(City)Party Committeeofficesand un its dire ctlyunder theOfficetooexcellence,pe ople -oriente drequire ments,strengthe nthe construction and ma nagementofthe Office tow

36、ards thework"a higher level".Investe e1.nking; re quirementsw e highlig ht pla ce feature s,putsuperiora ppr oachpolicy a nd locala ctualcombi ned up, put pr esentationoftheme thrust andmasse sof bythought bywants to combi ne d up;requirementsdrich ofconnotation.cond,the survey redecision

37、ag ood i dea,a n importa ntpartofa goodstaff.This year,tofocusaround industrialt ural structure,as one of the” ccl fomof vale sThe so did s rees tie objecve li ngs ae of novaue ad Ie vale of un. ea pespecve.Dfeetvaues, peoples be.a>， s,ways dHent. Pepeo_nted fcus onh - ava a. rea , nee. the br .a

38、ies masses as vale s A dee to e ope orbetid * s "mate Ie ecnomy more devel opme nt, mpove d i .a . cut ua pros” y, ad - ahapi er s deey conce nei t ha huma nveipme nt a. h - ava * deve opme nt of sc, and h a atonal uniid, ins_bd i n the maerai Cvl .i cHIzai on a nd spiiua cvizat ov eal a n.- et

39、 i f Seal st civ onta hgher level Asowant toseethat person's vaue .eeyounee,asoistomee Ienee - adthecmmuiyAdeetopeope oriee、to stongy aive everycommuh member,serveothes,be-i al tie commu niy of peopl. The sc d Oul ook ide s on there crd, inc - ig w to ate a recd of aci mentshowtau pefrmace a I d

40、 son. Wa es wa kid of Outlook hee topeopeore ntd lok, s ontheprrmieofrespeci ng the inteess ad po-we of pe I pl e ceat ng a popul a, mhe ats, sedy heat pefrma nneceaig、ve fr one olice, the be nei -" icheet s, ad o<eal cnstrct on of weloff sc* ad pr omoig Ie al r oud develpmet of pe oples pef

41、rma nne-ci evmet -lat accmplsmets, take aI othe 10k at the feciene-ofscil pr ogrss ca baandrua can” both had e nvrnme nt tsregt he a nd tae aothe l 00k at the si evio nment mpr lament momet-of d l opme nt a preent, de pedig onthe poteta for lusa nal e d lopme nt LLa<e pepe tolakboutae wrthlss and

42、 <e peopet o tak abou "Oul ook" s not wat t he pefrma nne.4. pepe resonne d to the sarig poit of te _esin, ad re- d t qust ons point Ma n s the sm ofsocilre ainshi ps W ca I not lev e te chchua nyngdu, hous ng,tu - m ad eeranmet, e nertii ng ad eveceai polt cal e cnomic cul ual ad scil

43、e nvionme nt and s on. IDe t luma n nee is, al w als of ie wl cme it o be ng Pepe crae fr thei luviva,a nd cont nneen.oig tereuls of tecnntr ucton. Ccloru i t he tansormain of te pepe of te worl d,cmmuniyviaiy i t he ceaion of ma. Thereore, any wk we do, the sat ng poit s huma, wha ae pepe. Us seld

44、u deelpment,tece of whic s t o mletthe nees if pe ople includig luviva nee dsemot ona lnne ds and latalzt needs.Itsoudbenoted that pe opl e ae not maci nes not te sae of a objec, not t becnt.- d. Pe opl e ha - thei ow pesnaiy, has is ow n pesnal iy,ha s is ow dg nity Pesn i I >e d of cae y ounned

45、to unndesad neld1mee. I s .ad t ha in the、-ulua sociey peple pl ant" i i_s_l scey .a n s a a "" "he if0rmi11nsciey,reu.目前，多晶硅薄膜生长技术主要有液相外延生长法、低压化学气相沉淀法、快热化学气相沉淀法、催化化学气相沉淀法、等离子增强化学气相沉淀法、超高真空化学气相沉淀法、固相晶化法和区熔再结晶法等。薄膜电池在很大程度上解决了太阳能电池的成本问题， 但是效率很低。目前商用薄膜电池的光电转换效率只有6%8%”。为了进一步提高太阳能电池的光

46、电转换效率，各国学者开始研究太阳能电池的效率极限和能量损失机理，并在此基础上提出了第三代太阳能电池的概念。表1各种太阳能电池技柑康太阳跳池种类量雕换效率%优点缺点单品优转解嬴技术成熟寿命长成本高长林、林毓,檄效聿雕魅脚品喊但也脑以“初始用112,8出定重量范工艺简单、转换费率氤成本 依廉稳定性总有拈岐率衰退 敏应多晶硅雕16砒成林版触较氤雕性好生户工舞要雌馥的脚蜿(CGIS)19,510.6楠光岐率如拆、髅串* 院性蛇工艺斛制和前是域需有相杀时料精勉SftffiCdS/CuS 屯肌曲端也他165及5成械乱转化麴高、易于大臊生 产3.3 .第三代太阳能电池太阳能转换成电能的卡诺循环效率可以达到9

47、5%而目前标准太阳能电池的理论转换效率上限为33% 这说明提高太阳能电池的效率还有很大的空间。为了进一步提高太阳能电 池的转换效率，新南威尔士大学对太阳能电池中能量损失机理进行了研究。图是太阳能电池能量损 失机理的示意图。图中为热损 失，和为 PN结和接触电压 损失，为电子-空穴结合所造 成的损失。由图可见，造成太阳能电 池的能量损失主要是热损失，光 生载流子对能很快将能带多余 的能量以热的形式损失掉；另一主要的能量损失是由电子-空穴对的重新结合引起的；还图2太阳能电池能量战失机理使得光子的能量激发出的光生载流子没有多余的能量可以有一部分能量损失是由 PN结和 接触电压损失引起的。 为减少热

48、损失，可以设法让通过太阳能电 池的光子能量刚刚大于能带能量，损失。为减少电子-空穴结合所造成的损失， 可设法延长光生载流子的寿命，这可以通过消tomeet. It s sad t hat in the、-ulua society people pi ant"、,s.i society ma n s ana nima" "he fnsocey,r s one of the”ccl fomof valesThe so ues rees tie objecve li ngs ae of novaue ad Ie vale of fun. ea pespecve. Dff

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54、nne - ad the cmmuniy Aedig onIe pote Ia for lusanal e d l I pmee ae not maci nes not Iesaw of a objec,dee t o pe ope orieed to 1110ngy Idvcae eveycommu. m - be,ve oIes, be-i al IIe commu. of peple T he sc- d I ooknI LLa- pepe i、. aboule,ae wrIlss and peope t oak abou "Oul ook" is not what

55、t he pefrma nne.I be cntr- d. Pe opl e ha - their ow pesnaiIy has is ow n pesnal iy, hhs is own dig niy Pesn id of cae y ounnedto unndesad neld叠层太阳电池的制备可以通过两种方式得到。太阳电池，一个是高带宽的，另一个则是低带宽的,太酊电池能常下降图3叠层太阳电池的机理能带2（中网帝）能帮1I价电子带）除不必要的缺陷来实现。减小PN结的接触电压损失，可以通过聚集太阳光，加大光子密度的方法来实现。基于以上分析，澳大利亚和美国分别提出了第三代太阳能电池的概念。

56、当然，目前第三代太阳能电池主要还在进行概念和简单实验研究。第三代太阳能电池主要有前后重叠电池， 多能带电池，热太阳能电池，热载流子电池，和冲击离子化太阳能电池等。4 .第三代新型太阳能电池的介绍4.1. 叠层太阳能电池一种是机械堆叠法，先制备出两个独立的然后把高带宽的堆叠在低带宽的电池上面；另一种是一体化的方法，电池间通过隧道结串接。在多结叠层串 接太阳电池中，由于各分电池由 P-N结组成，如果直接串联在一起， 则由于P-N结反偏而不导电，采用隧道结结构可以解决这一问题。据分析，无限增加太阳电 池的层数，理论上可获得的最高效 率为86.8%。4.2. 多能带太阳能电池多能带电池也称为不纯能带电池，最简单的就是3能带电池，基本原理如图 8所示。能带1和能带3是大块结晶中的价电子带和传导带，能带2是人工制备的中间能带。这样， 高能量范围内的太阳光（hv >Ei3）引起能带1和3间的转移，而中间能量范围的太阳光引 起能带1和2以及能带2和3间的转移而被吸收，这是覆盖更宽的太阳光谱的尝试。因此, 和多结太阳电池的情形一样，对削减短波长域的能量损失有较好的