第五章-4 有机太阳电池OPV-20141204

1、Organic Materials for electronics & Photonics第五章 1 CdTe太阳电池 2 CuInGaSe2(CuInS2)太阳电池 3 染料敏化太阳电池(DSSC) 4 有机太阳电池(OPV)有机太阳电池(OPV, Organic Photovoltaics, OSC, Organic Solar CellsOPV结构及机理Why OPV?3 1OPV制备过程3 33 4OPV发展历程3 2OPV性能的影响要素3 5OPV的发展现状及挑战3 6Why OPVs?Organic Materials for electronics & Photo

2、nicsAdvantages of OPVs -Processed easily over large area -spin-coating -doctor blade techniques (wet-processing) -evaporation through a mask (dry processing) -printing -Low cost -Low weight -Mechanical flexibility and transparency -Band gap of organic materials can be easily tuned chemically by inco

3、rporation of different functional groupOrganic Materials for electronics & Photonics重量重量轻轻成本低成本低Why OPVs? (Application)Organic Materials for electronics & PhotonicsWhy OPVs? (Application)Why OPVs? (Application)Organic Materials for electronics & PhotonicsOrganic Materials for electronics

4、 & PhotonicsRequirement of OPVsSource: Siemens AGOrganic Materials for electronics & PhotonicsHistory of OPVsOrganic Materials for electronics & Photonics(MgPh, 200mV)(MgPh, 200mV)(Polymer/C60)(Polymer/C60)In 2010, Solarmer Energy, Inc: 8.13%; Konarka: 8.3%.In 2011, Mitsubishi Chemical C

5、orp : 8.5%; South China Univerisity of Technology曹镛院士组：8.37%; 2014年8月，10.7%; In 2012, Konarka : 9%;In 2011, Dou, L. et al (UCLA): 8.62% Nature Photon. 6, 180185 (2012). In 2012, Heliatek: 10.7%;Sumitomo Chemical of Japan: 10.6%; In Jan 2013, Heliatek: 12%Single Junction Solar Cell:Single Junction So

6、lar Cell:Tandem Solar Cell:Tandem Solar Cell:Organic Materials for electronics & Photonics有机太阳能电池的结构glassITOLiFglassADA+DAlOrganic Materials for electronics & PhotonicsOrganic Materials for electronics & PhotonicsOrganic Materials for electronics & PhotonicsOrganic or polymer single-

7、layer PVsDisadvantageOrganic Materials for electronics & PhotonicsOrganic Materials for electronics & Photonics有机太阳能电池的基本原理 Light is absorbed in the polymer layer Absorption creates a bound electron-hole pair (exciton) Exciton is split into separate charges which are collected at contactsDon

8、orAcceptorOrganic Materials for electronics & PhotonicsOrganic Materials for electronics & PhotonicsOPV制备过程（以体异质结OPV为例） Organic Materials for electronics & PhotonicsOPV制备过程（以体异质结OPV为例） Organic Materials for electronics & PhotonicsOrganic Materials for electronics & PhotonicsOrgan

9、ic Materials for electronics & PhotonicsOrganic Materials for electronics & PhotonicsOrganic Materials for electronics & Photonics有机物成膜：有机物成膜：将给体材料将给体材料( (如如P3HT)P3HT)和受体材料（如和受体材料（如PCBMPCBM）充分溶解、搅拌并过滤后，滴至缓冲）充分溶解、搅拌并过滤后，滴至缓冲层表面上，旋涂成膜。层表面上，旋涂成膜。Organic Materials for electronics & Photo

10、nicsOrganic Film PreparationOrganic Materials for electronics & PhotonicsOrganic Film PreparationOrganic Materials for electronics & PhotonicsOPV活性层制备过程阴极溅射或蒸发镀膜：阴极溅射或蒸发镀膜：将涂过活性层的电池上贴上高温胶带或者掩模板后，放入磁控溅射仪或者高真空将涂过活性层的电池上贴上高温胶带或者掩模板后，放入磁控溅射仪或者高真空镀膜系统内生长无机缓冲层和金属膜。镀膜系统内生长无机缓冲层和金属膜。OPV性能的影响要素l 给受体材

11、料l 电极l 界面修饰l 形貌控制l 结构设计 Organic Materials for electronics & Photonics活性层材料给体材料pentaceneSmall Molecule DonorsCuPcF16CuPCZnPc*OOMDMO-PPV*S*P3HTNN*PFBPolymer DonorsOrganic Materials for electronics & Photonics受体材料的选择Organic Materials for electronics & PhotonicsMaterials for BHJ organic sola

12、r cellC60C70ICBAICMAPC61BMPC71BMPC71HM电极材料的选择阳极：阳极：功函数较高且透明或半透明的金属或导电聚合物、导电氧化物。ITO有较高的功函数，在可见光和近紫外区有良好的透过率。阴极：阴极：阴极材料主要是功函数较低的金属构成的，如Mg、Al、Ca、Ag，其中Al最为常用。Organic Materials for electronics & Photonics界面修饰材料阳极界面修饰材料无机界面修饰材料：MoO3、WO2、V2O5等有机界面修饰材料：PEDOT:PSS阴极界面修饰材料无机界面修饰材料：LiF、ZnO、TiO2等有机界面修饰材料：PFN

13、PFNPFN优化器件性能的几个方面：Poly-N-dodecyl-2,5-bis(2-thienyl)pyrrole-2,1,3-benzothiadiazole: PTPTBthe push-pull concept by altering electron rich N-dodecyl-2,5-bis(2-thienyl)pyrrole and electron deficient 2,1,3-benzothiadiazole groups1: Low bandgap polymerBandgap engineeringEr : the energy contribution from b

14、ond length alternation RE : the resonance energyE : the energy caused by the inter ring torsion angle ESUB : the influence of the substituents. EG = Er + RE + E + Esub1. Aromatic(芳香族的) form shows higher stabilization energy and therefore the higher bandgap.2. Resonance energy leads to an energy stab

15、ilization and so to an increased splitting of the HOMO-LUMO energy.3. Torsion between the ring plain interrupts the conjugation and therefore increases the bandgap.4. Electron donating groups(推电子基团)raise the HOMO level and electron withdrawing groups (拉电子基团) lower the LUMO.5. In the solid phase, add

16、itional intermolecular effects between the chains have to be taken into account, which generally leads to broader bands and a lower bandgap.Organic Materials for electronics & PhotonicsSynthetic strategy1. Introduction of side groups:increase or decrease the electron density2. Push-pull polymers

17、:The bandgap of copolymers with alternating of electron rich and electron poor compounds can decrease significantly. (The bond length alternation is reduced and so the Peierls stabilisation.)3. Introduction of methine (次甲基次甲基)groups between the ring systems:The quinoid(醌型化合物) form minimize the inter

18、 annular rotation by the double bond character of the bridge bonds as well as the bond length alternation . (The structure becomes more flat and theresonance between the rings is increased.)Which is the Voc?Is it in the electrodes? (MIM picture) VocIs it in the bulk-heterojunction? (p/n-like picture

19、) Voc2: Origin of open-circuit voltage (Voc)TOP ELECTRODEWORK FUNCTION eVCa2.87Al4.28Ag4.26Au5.1Organic Materials for electronics & PhotonicsS1 S2Voc in plastic solar cell is directly related to the acceptor strength of the fullerene.The variation of negative electrode work function influences t

20、he Voc in only a minor way.Variation of VocOrganic Materials for electronics & Photonics3: 形貌和载流子传输morphology and transportAlkoxy-PPVPCBMOrganic Materials for electronics & PhotonicsPL quenchingmorphology and transportOrganic Materials for electronics & Photonics4: Optimization of morpho

21、logyVoc = 810 mVISC = 5.2 mA/cm2FF = 0.62 = 3 %IPCEmax = 50 %EQE = 8090 %The efficiency is strongly enhanced byusing cholorobenzene in MDMO-PPV /PCBM mixture.Organic Materials for electronics & PhotonicsP3HT post production treatment: increased absorption strength in the red Higher conversion ef

22、ficiency Diode characteristics is improved5: 其它处理技术“post production treatment”Organic Materials for electronics & Photonics6: 理想的分子结构“Double Cable” polymersBoth donor and acceptor phases will be percolated at very low filling into a host polymerIsc = 0.42 mA/cm2 Voc = 0.83 VFF = 0.29 (white ligh

23、t 88mW/cm2)Organic Materials for electronics & PhotonicsHybrid polymer/nanoporous TiO2 system Almost all excitons can be split No deadends Polymer chains can be aligned Easy to model Semiconductors can be changedwithout changing the geometry.For efficient photoinduced charge generationTiO2 can b

24、e easily patterned into a continuous network for electron transport.OPV 的产业现状u 美国 Konarka 公司： In 2008, Konarka introduced Power Plastic to the commercial market. Konarkas first-generation flexible PSC panel has a three-year lifetime with flexible encapsulation.u德国Heliatek公司： Currently seeking to rai

25、se 60 million from investors to equip and install a new 75MW roll-to-roll production line in Dresden, Germany. Initial volume production of its OPV technology is set for the third quarter of 2012.u美国Solarmer Energy, Inc： Solarmer is targeting three major applications areas for plastic solar panels: consumer & portable electronics, building-integrated photovoltaics (BIPV), and smart fabrics. Some products will be available in 2011 or 2013.Heliatek world record cells with 12.0% efficiency on an Heliatek world record