光伏效應(yīng)及其光電轉(zhuǎn)化理論馬貴軍

1、光伏效應(yīng)(xioyng)及其光電轉(zhuǎn)化理論 報(bào)告人：馬貴軍 研究課題：光催化分解硫化氫研究 指導(dǎo)(zhdo)教師：李 燦 研究員中國(guó)科學(xué)院大連化學(xué)物理研究所503組Seminar 2008年5月27日共二十二頁(yè)報(bào)告(bogo)內(nèi)容概念介紹研究進(jìn)展結(jié)論(jiln)與展望參考文獻(xiàn)共二十二頁(yè)概念(ginin)介紹1839年: 法國(guó)(f u)科學(xué)家貝克雷爾(Becqurel)發(fā)現(xiàn)，光照能使半導(dǎo)體材料的不同部位之間產(chǎn)生電位差。這種現(xiàn)象后來(lái)被稱為“光生伏打效應(yīng)”，簡(jiǎn)稱“光伏效應(yīng)”1954年: 美國(guó)科學(xué)家恰賓和皮爾松在美國(guó)貝爾實(shí)驗(yàn)室首次制成了實(shí)用的單晶硅太陽(yáng)電池(6)，誕生了將太陽(yáng)光能轉(zhuǎn)換為電能的實(shí)用光伏發(fā)電

2、技術(shù)。光伏效應(yīng)(Photovoltaic effect): 指光照使不均勻半導(dǎo)體或半導(dǎo)體與金屬結(jié)合的不同部位之間產(chǎn)生電位差的現(xiàn)象。它首先是由光子（光波）轉(zhuǎn)化為電子、光能量轉(zhuǎn)化為電能量的過(guò)程；其次，是形成電壓過(guò)程。有了電壓，就像筑高了大壩，如果兩者之間連通，就會(huì)形成電流的回路。 共二十二頁(yè)光伏效應(yīng)(xioyng)應(yīng)用光催化降解有機(jī)(yuj)污染物光催化有機(jī)合成太陽(yáng)能光電池太陽(yáng)能光解水、甲醇、生物質(zhì)制氫 . . . . . .共二十二頁(yè)e- - - - - - - - - - - - + + + + + + + + +h+空間電荷區(qū)內(nèi)建電場(chǎng)(din chng)空穴(kn xu)擴(kuò)散力電子擴(kuò)散力概念

3、介紹節(jié)P型n型共二十二頁(yè)_+(C/cm3)+eNd-eNaxpxpxnxnNaxp=Ndxn概念(ginin)介紹節(jié)e- - - - - - - - - - - - + + + + + + + + +h+P型n型共二十二頁(yè)C= ；2(Vd - Va) . (1Na + 2Nd)q 12 NdNa1/C2=_+(C/cm3)+eNd-eNaxpxnVaVa+dVC：電容Vd:內(nèi)建電勢(shì)Va:外加電壓:介電常數(shù)N：攙雜(chnz)濃度+dQ-dQdQdVa概念(ginin)介紹節(jié)共二十二頁(yè)Back and Front contact: 導(dǎo)出電荷(dinh)Anti reflection coatin

4、g: 增加光吸收P- and N-type semiconductor: 產(chǎn)生電荷Cover glass: 保護(hù)電極光伏電池(dinch)基本原理IVDarkLightVocIphIscMaximumPower pointVmpImpI-V curve共二十二頁(yè)概念介紹(jisho)光伏電池AM1.5: 太陽(yáng)光以41.8的角度入射到水平面，輻照通量為963 W/m2 (為了方便，通常規(guī)定為1000 W/m2 )。短路光電流(Isc): 太陽(yáng)能電池在短路條件(tiojin)下的工作電流，短路電流等于光子轉(zhuǎn)換成的電子-空穴對(duì)的絕對(duì)數(shù)量，此時(shí)電池輸出的電壓為零。開(kāi)路電壓(Voc):太陽(yáng)能電池在開(kāi)路條

5、件下的輸出電壓，此時(shí)電池的輸出電流為零。共二十二頁(yè)概念(ginin)介紹光伏電池填充(tinchng)因子(FF):電池在不同的負(fù)載條件下，輸出的功率是不一樣的。FF=Pmax/IscVoc, Pmax為最大輸出功率。入射光子到電子的轉(zhuǎn)換效率(IPCE): IPCE是描述太陽(yáng)能電池在單色光作用下的轉(zhuǎn)換效率指標(biāo)，定義為：IPCE=轉(zhuǎn)移到外電路的電子數(shù)/入射的光子數(shù)。IPCE的大小決定于：1)光捕獲效率LHE(), 2)電荷注入效率(inj), 3) 電荷收集效率(e)。能量轉(zhuǎn)換效率():太陽(yáng)能電池的最大功率輸出與入射光的能量(Plight)之比。共二十二頁(yè)A. Goetzbergera et a

6、l., Photovoltaic materials, history, status and outlook, Materials Science and Engineering R 40 (2003) 146 Requirements for the ideal solar cell material are: bandgap between 1.1 and 1.7 eV; direct band structure; consisting of readily available, non-toxic materials; easy, reproducible deposition te

7、chnique, suitable for large area production;good photovoltaic conversion efficiency; long-term stability.光伏電池材料(cilio)要求h (eV)共二十二頁(yè)幾種最主要(zhyo)的光伏電池Type of cellEfficiency (%)Research and technology needsCellModuleCrystalline silicon2410-15Higher production yields, lowering of cost and energy contentM

8、ulticrystalline silicon189-12Lower manufacturing cost and complexityAmorphous silicon137Lower production costs, increase production volume and stabilityCuInSe21912Replace indium (too expensive and limited supply), Replace CdS window layer, scale up productionDye-sensitized nanostructured materials10

9、-117Improve efficiency and high-temperature stability, scale up productionBipolar AlGaAs/Si photoelectrochemical cell19-20-Reduce materials cost, sale upOrganic solar cell2-3-Improve stability and efficiencyM. Grtzel, Photoelectrochemical cells, Nature 2001(414), 338共二十二頁(yè)MultijunctionSiCu(In,Ga)Se2D

10、ye cell幾種最主要(zhyo)的光伏電池共二十二頁(yè)硅基光伏電池(dinch)Adolf Goetzbergera, Christopher Heblinga, Hans-Werner Schock Photovoltaic materials, history, status and outlook. Materials Science and Engineering R 40 (2003) 146Although crystalline silicon is not the optimal material from a solid state physics point ofview

11、 it dominates the market and will continue to do this for the next 510 years.共二十二頁(yè)CdTe-CdS光伏電池(dinch) Adolf Goetzbergera, Christopher Heblinga, Hans-Werner Schock Photovoltaic materials, history, status and outlook Materials Science and Engineering R 40 (2003) 146Efficiencies: above 16%Bandgap close

12、 to the optimum for solar energy conversionEasy to handle in thin-film deposition processesCd：toxic materialThe difficulty of doping p-type CdTeThe difficulty in the recombination losses associated with the junction interface共二十二頁(yè)CIGS 光伏電池(dinch)Adolf Goetzbergera, Christopher Heblinga, Hans-Werner

13、Schock Photovoltaic materials, history, status and outlook. Materials Science and Engineering R 40 (2003) 146Efficiencies: 1118%共二十二頁(yè)染料(rnlio)敏化光伏電池原理示意圖Adolf Goetzbergera,Christopher Heblinga, Hans-Werner Schock Photovoltaic materials, history, status and outlook. Materials Science and Engineering

14、R 40 (2003) 146The conduction mechanism is based on a majority carrier transport as opposed to the minority carrier transport of conventional inorganic cells.Instability over the time and the temperature range which occurs under outdoor conditionsEfficiencies : 711%共二十二頁(yè)有機(jī)(yuj)光伏電池Extremely high opt

15、ical absorption coefficientsEase of large-scale manufacturing at low-temperature processes and very low costsThe width of the charge generation layer is much smaller than inorganic cells. Holger Spanggaard, Frederik C. Krebs, A brief history of the development of organic and polymeric photovoltaics,

16、Solar Energy Materials & Solar Cells 83 (2004) 125146Adolf Goetzbergera, Christopher Heblinga, Hans-Werner Schock Photovoltaic materials, history, status and outlook. Materials Science and Engineering R 40 (2003) 146Efficiencies : 4.3%共二十二頁(yè)World PV Cell/Module ProductionPhotovoltaics is one of the f

17、astest growing industries at present. In the last five years, the production of photovoltaic cells has increased steadily by an average of 40% per yearArnulf Jger-Waldau, PV Status Report 2003, European Commission, DG JRC, Institute for Environment and Sustainability, Renewable Energies Unit, (2003)

18、, p4我國(guó)在光伏電池市場(chǎng)(shchng)所占的份額還很低，國(guó)家需快速加大在這一領(lǐng)域的投資力度共二十二頁(yè)參考文獻(xiàn)虞麗生. 半導(dǎo)體異質(zhì)節(jié)物理. 北京(bi jn): 科學(xué)出版社, 2006, 30.姜月順, 李鐵津. 光化學(xué). 北京: 化學(xué)工業(yè)出版社, 2005, 295.Donald A. Neamen. Semiconductor Physics and devices. 2005, 75.Arnulf Jger-Waldau, PV Status Report 2003, European Commission, DG JRC, Institute for Environment and Sustainability, Renewable Energies Unit, 2003, 4A. Goetzbergera et al. Mater. Sci. Eng. R 40 2003, 1.M. Grtzel. Nature 2001, 338.M. Grtzel et al. Acc. Chem. Res. 2000, 269.Kannan Ramanathan et al. Prog. Photovolt: Res. Appl., 2003, 225.共二十二頁(yè)謝謝(xi xie)大家！共二十二頁(yè)內(nèi)容摘要光伏效應(yīng)及其光電轉(zhuǎn)化理論。這種現(xiàn)象后來(lái)