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Hongwei Han - One of the best experts on this subject based on the ideXlab platform.
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low temperature fabrication of carbon electrode based Hole Conductor free and mesoscopic perovskite solar cells with power conversion efficiency 12 and storage stability 220 days
Applied Physics Letters, 2020Co-Authors: Tingting Shi, Hongwei Han, Bingchu Yang, Yongbo Yuan, Yongli Gao, Siyuan Lin, Mei Fang, Deming Kong, Conghua ZhouAbstract:A low-temperature fabrication routine is developed for Hole-Conductor-free and mesoscopic perovskite solar cells using a TiO2 nanoparticle-binding carbon electrode as the top electrode. Vacuum treatment is adopted to help the infiltration and formation processes of the organic–inorganic hybrid perovskite crystallites. It is observed that such treatment not only condenses the mesoporous skeleton and improves film conductance of the carbon electrode but also makes the perovskite crystallites grow in the core part of the mesoporous skeleton. As such, the extraction process of photogenerated charge carriers is accelerated due to the strengthened interfacial contact between the perovskite crystallites and the skeleton. Accordingly, the photo-to-electric power conversion efficiency of the low-temperature devices is upgraded from 7.38 (±1.40)% to 10.17 (±0.86)% (optimized at 12.29%, AM 1.5 G, 100 mW/cm2). In addition, prolonged stability is observed. Due to the condensed device structure, storage stability of 225 days has been achieved in ambient air (with relative humidity of about 40–60%), even without encapsulation. The proposed strategy is helpful in further reducing the production cost.
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Hole-Conductor-free perovskite solar cells
MRS Bulletin, 2020Co-Authors: Deyi Zhang, Yaoguang Rong, Anyi Mei, Hongwei HanAbstract:Metal-halide perovskite solar cells (PSCs) have become a promising candidate for photovoltaic applications. Current popular organic Hole Conductors for highly efficient PSCs bring cost and stability issues, which hinder the commercialization of the PSCs. Hole-Conductor-free PSCs are attracting great interest because they eliminate the adverse effects of organic Hole Conductors by transporting Holes in the perovskite itself. In this article, we summarize recent progress in conventional, inverted, and printable mesoscopic Hole-Conductor-free PSCs. Specifically, we emphasize the stunning stability and scale-up manufacturing of printable Hole-Conductor-free PSCs, discussing their potential from laboratory to market. The causes for Hole-Conductor-free PSCs’ current low efficiency are also discussed, and are primarily ascribed to energy-level alignment and interface recombination. We believe that the efficiencies of Hole-Conductor-free PSCs can be enhanced to be comparable with Hole-Conductor-containing PSCs by interface modification and material design.
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printed Hole Conductor free mesoscopic perovskite solar cells with excellent long term stability using peai as an additive
Journal of Energy Chemistry, 2018Co-Authors: Zheling Zhang, Yusong Sheng, Pei Jiang, Hongwei Han, Jian ZhangAbstract:Abstract Phenethylamine (PEA) was successfully introduced into Hole-Conductor-free, fully printable mesoscopic MAPbI3 perovskite solar cells (MPSCs) with a carbon electrode by mixing phenethylammonium iodide with MAPbI3 perovskite solution. PEA-MAPbI3 films show better pore filling into TiO2 scaffold that forms better contact, and induce longer exciton lifetime and higher quantum efficiency of photoinduced charge separation. As a result, the power conversion efficiency of PEA-MAPbI3 MPSCs is 37% higher than that of MAPbI3 MPSCs. And PEA-MAPbI3 MPSCs show excellent long-term stability that could keep 90% of origin power conversion efficiency for over 80 days in the air.
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fully printable Hole Conductor free mesoscopic perovskite solar cells based on mesoporous anatase single crystals
New Journal of Chemistry, 2018Co-Authors: Yuli Xiong, Yusong Sheng, Anyi Mei, Yong Liu, Kun Lan, Dongyuan Zhao, Hongwei HanAbstract:Mesoporous anatase singe crystal provides a large surface area and less carrier traps as compared to polycrystals; however, it is generally prepared with a particle size in micrometers by a complex method; this hinders its application as electron transport materials (ETMs) for mesoscopic perovskite solar cells (MPSCs). Herein, we fabricated a small-sized mesoporous anatase single crystal with a large surface area (169 m2 g−1) and an oliver-shape (about 120 nm in length and 60 nm in width) by a simple method and applied it as an ETM into a Hole-Conductor-free fully printable MPSC. As expected, a high-quality film was formed, and the device showed an obvious increase in efficiency as compared to the P25 (commercial TiO2)-based device due to the faster electron extraction from perovskite to the ETM. This suggests that the mesoporous anatase single crystal is a promising ETM candidate for producing efficient fully-printable Hole-Conductor-free MPSCs.
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Fully printable Hole-Conductor-free mesoscopic perovskite solar cells based on mesoporous anatase single crystals
New Journal of Chemistry, 2018Co-Authors: Yuli Xiong, Yusong Sheng, Anyi Mei, Yong Liu, Kun Lan, Dongyuan Zhao, Hongwei HanAbstract:Mesoporous anatase single crystal titania with a small particle size was introduced into fully printable Hole-Conductor-free hybrid solar cells, which shows an optimal electron transport and carrier lifetime, leading to an enhanced device performance.
Yaoguang Rong - One of the best experts on this subject based on the ideXlab platform.
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Hole-Conductor-free perovskite solar cells
MRS Bulletin, 2020Co-Authors: Deyi Zhang, Yaoguang Rong, Anyi Mei, Hongwei HanAbstract:Metal-halide perovskite solar cells (PSCs) have become a promising candidate for photovoltaic applications. Current popular organic Hole Conductors for highly efficient PSCs bring cost and stability issues, which hinder the commercialization of the PSCs. Hole-Conductor-free PSCs are attracting great interest because they eliminate the adverse effects of organic Hole Conductors by transporting Holes in the perovskite itself. In this article, we summarize recent progress in conventional, inverted, and printable mesoscopic Hole-Conductor-free PSCs. Specifically, we emphasize the stunning stability and scale-up manufacturing of printable Hole-Conductor-free PSCs, discussing their potential from laboratory to market. The causes for Hole-Conductor-free PSCs’ current low efficiency are also discussed, and are primarily ascribed to energy-level alignment and interface recombination. We believe that the efficiencies of Hole-Conductor-free PSCs can be enhanced to be comparable with Hole-Conductor-containing PSCs by interface modification and material design.
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Amide Additives Induced a Fermi Level Shift To Improve the Performance of Hole-Conductor-Free, Printable Mesoscopic Perovskite Solar Cells.
The journal of physical chemistry letters, 2019Co-Authors: Shuang Liu, Yusong Sheng, Yaoguang Rong, Deyi Zhang, Qifei Wang, Yue Ming, Anyi MeiAbstract:Solution-processable organic-inorganic perovskite solar cells have attracted much attention in the past few years. Energy level alignment is of great importance for improving the performance of perovskite solar cells because it strongly influences charge separation and recombination. In this report, we introduce three amide additives, namely, formamide, acetamide, and urea, into the MAPbI3 perovskite by mixing them directly in perovskite precursor solutions. The Fermi level of MAPbI3 shifts from -4.36 eV to -4.63, -4.65, and -4.61 eV, respectively, upon addition of these additives. The charge transfer between perovskite and mp-TiO2 is found to be promoted as determined via TRPL spectra, and recombination in the perovskite is suppressed. As a result, the built-in electric field (Vbi) of the printable, Hole-Conductor-free mesoscopic perovskite solar cells based on these perovskites with amide additives is enhanced and a peak power conversion efficiency of 15.57% is obtained.
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Efficient Hole-Conductor-free printable mesoscopic perovskite solar cells based on SnO2 compact layer
Electrochimica Acta, 2018Co-Authors: Xixi Jiang, Yuli Xiong, Yaoguang Rong, Anyi Mei, Yingxia Jin, Chengbo Tian, Zhihui Zhang, Jin Zhang, Yumin Zhang, Hongwei HanAbstract:Abstract TiO 2 compact layer (c-TiO 2 ) is generally applied for high-efficiencies perovskite solar cells (MPSCs), but it shows a relatively low electron mobility, which may restrict some performance of the MPSCs. Herein, we demonstrated SnO 2 compact layer (c-SnO 2 ), which prepared by spray pyrolysis using a solution of dibutyltin bisacetylacetonate in ethanol, could be an excellent alternative compact layer for efficient Hole-Conductor-free printable MPSCs. The best device with such a c-SnO 2 has achieved an efficiency of 13.77%, which is very comparable to that obtained by the device based on c-TiO 2 . Furthermore, the device with c-SnO 2 showed less pronounced hysteresis effect, probably because of the higher electron mobility of SnO 2 and less charge accumulation at the interfaces. The simple preparation process and improved hysteretic behavior pave the way for industrialization of PSCs.
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printable carbon based Hole Conductor free mesoscopic perovskite solar cells from lab to market
Materials Today Energy, 2017Co-Authors: Miao Duan, Yaoguang Rong, Anyi Mei, Hongwei HanAbstract:Abstract Organic-inorganic hybrid lead halide perovskite solar cells (PSCs) have rapidly emerged at forefront of photovoltaic technologies with a certified power conversion efficiency of 22.1%. Among different types of PSCs, printable carbon-based Hole-Conductor-free perovskite solar cells (CPSCs) have been gradually recognized as the most promising PSCs for commercialization for the advantages of low cost, high stability and easy fabrication. Herein, we highlight the recent advances of the printable Hole-Conductor-free CPSCs, including perovskite modification, optimization of each functional layers, perovskite deposition technology and post-treatment. Additionally, the large-scale perovskite solar modules manufactured by screen-printing technology are introduced and the promising research directions for Hole-Conductor-free CPSCs to promote the commercialization in the future are proposed.
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Boron-Doped Graphite for High Work Function Carbon Electrode in Printable Hole-Conductor-Free Mesoscopic Perovskite Solar Cells.
ACS applied materials & interfaces, 2017Co-Authors: Miao Duan, Yusong Sheng, Pei Jiang, Yuli Xiong, Yaoguang Rong, Anyi Mei, Chengbo Tian, Xiaomeng HouAbstract:Work function of carbon electrodes is critical in obtaining high open-circuit voltage as well as high device performance for carbon based perovskite solar cells. Herein, we propose a novel strategy to upshift work function of carbon electrode by incorporating boron atom into graphite lattice and em-ploy it in printable Hole-Conductor-free mesoscopic perovskite solar cells. The high-work-function boron-doped carbon electrode facilitates Hole extraction from perovskite as verified by photoluminescence. Meanwhile, the carbon electrode is endowed with an improved conductivity due to a higher graphitization carbon of boron-doped graphite. These advantages of the boron-doped carbon electrode result in a low charge transfer resistance at carbon/perovskite interface and an extended carrier re-combination lifetime. Together with the merit of both high work function and conductivity, the power conversion efficiency of Hole-Conductor-free mesoscopic perovskite solar cells is increased from 12.4 % for the pristine nee...
Wei Huang - One of the best experts on this subject based on the ideXlab platform.
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diameter engineering on tio2 nanorod arrays for improved Hole Conductor free perovskite solar cells
Solar Energy, 2018Co-Authors: Wei Liu, Liang Chu, Rui Zhang, Jianping Yang, Wei Huang, Jian ZhangAbstract:Abstract TiO2 nanorod arrays (NAs) have been successfully applied in mesoporous perovskite solar cells (PSCs) due to the direct electron transfer channels, and previous focus has been mainly on the length of TiO2 NAs to improve the performance. To date, diameter engineering without changing length is still a big challenge, which is another key factor on the performance of TiO2 NAs-based PSCs. Here, the diameter of TiO2 NAs was effectively engineered by annealing temperatures from 100 °C to 500 °C to enhance the crystallinity and surface smoothness of TiOx seed-layers, which restrained the transverse direction to decrease the average diameter of TiO2 NAs from 74 to 31 nm via the Steric effect. In addition, the smooth TiOx seed-layers improved the vertical orientation of the TiO2 NAs. The TiO2 NAs were further applied as photoanodes in carbon-based PSCs without Hole Conductor layers. The fine and vertical TiO2 NAs enhance the performance of PSCs, which mainly results from the improved charge transfer and excellent transmission. The carbon-based PSCs with 31 nm TiO2 NAs achieved the best performance with power conversion efficiency (PCE) up to 10.15%, which is higher than 7.18% of that based on the common TiO2 nanoparticles. Therefore, our findings suggest that the annealing of seed-layers at different temperatures is a feasible and effective strategy to acquire diameter engineering on TiO2 NAs for high performance PSCs.
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a facile and green approach to synthesize mesoporous anatase tio2 nanomaterials for efficient dye sensitized and Hole Conductor free perovskite solar cells
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Liang Chu, Wei Liu, Rui Zhang, Jian Yang, Wei Huang, Jie ZhangAbstract:Mesoporous anatase TiO2 nanomaterials (MATNs) with both large specific surface areas and structural coherence are highly desirable to achieve excellent physicochemical properties for photovoltaic applications, but the existing synthesis methods either need templates or cause pollution. Herein we report a simple, template-free, and green approach to synthesize MATNs consisting of interconnected nanoparticles. The Ti-complex intermediates were first prepared using titanium isopropoxide and acetic acid in a solvothermal reaction, which went through a morphology transformation sequence of nanowires, microspheres, and microflowers with a prolonged reaction time. Then the Ti-complex intermediates were cracked into MATNs under annealing, which were applied in dye-sensitized solar cells (DSSCs) and Hole-Conductor-free perovskite solar cells (HPSCs). The mesoporous anatase TiO2 nanowire-based DSSCs achieved a high power conversion efficiency (PCE) up to 7.78% because of both a high dye-adsorption capacity and long...
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A Facile and Green Approach to Synthesize Mesoporous Anatase TiO2 Nanomaterials for Efficient Dye-Sensitized and Hole-Conductor-Free Perovskite Solar Cells
2018Co-Authors: Liang Chu, Wei Liu, Rui Zhang, Jian Yang, Jie Zhang, Wei HuangAbstract:Mesoporous anatase TiO2 nanomaterials (MATNs) with both large specific surface areas and structural coherence are highly desirable to achieve excellent physicochemical properties for photovoltaic applications, but the existing synthesis methods either need templates or cause pollution. Herein we report a simple, template-free, and green approach to synthesize MATNs consisting of interconnected nanoparticles. The Ti-complex intermediates were first prepared using titanium isopropoxide and acetic acid in a solvothermal reaction, which went through a morphology transformation sequence of nanowires, microspheres, and microflowers with a prolonged reaction time. Then the Ti-complex intermediates were cracked into MATNs under annealing, which were applied in dye-sensitized solar cells (DSSCs) and Hole-Conductor-free perovskite solar cells (HPSCs). The mesoporous anatase TiO2 nanowire-based DSSCs achieved a high power conversion efficiency (PCE) up to 7.78% because of both a high dye-adsorption capacity and long charge-transfer channels, while the PCE based on the P25 photoelectrodes is 6.61%. The further application of mesoporous anatase TiO2 nanowires in HPSCs achieved an improved PCE of 8.52%, compared to 6.78% for cells prepared using the P25 electrodes
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Inverse-architecture perovskite solar cells with 5,6,11,12-tetraphenylnaphthacene as a Hole Conductor
RSC Advances, 2017Co-Authors: Cheng-xin Wang, Hao Hao, Shufen Chen, Kun Cao, Qin Zhang, Guangjian Wan, Wenjuan Shang, Wei HuangAbstract:Rubrene was applied into MAPbI3-based perovskite solar cells as a Hole Conductor and a high efficiency of 14.3% was achieved.
Anders Hagfeldt - One of the best experts on this subject based on the ideXlab platform.
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the effect of mesoporous tio2 pore size on the performance of solid state dye sensitized solar cells based on photoelectrochemically polymerized poly 3 4 ethylenedioxythiophene Hole Conductor
Electrochimica Acta, 2016Co-Authors: Jinbao Zhang, Erik M. J. Johansson, Meysam Pazoki, Justus Simiyu, Malin B Johansson, Ocean Cheung, Leif Haggman, Nick Vlachopoulos, Anders HagfeldtAbstract:Abstract Photoelectrochemical polymerization of poly(3,4-ethylenedioxythiphene) (PEDOT) has recently been introduced and widely investigated for fabrication of the Hole transporting material (HTM) in highly efficient solid state dye sensitized solar cells (sDSCs). In this work, the effects of the surface area and pore size of TiO2 film were for the first time investigated in the sDSCs employing the in-situ polymerizated PEDOT HTM. Three different varieties of mesoporous TiO2 particles with controllable surface area and pore size were synthesized through the basic route in order to study the corresponding sDSC photovoltaic performances. It was found that the pore size plays an important role in the kinetics of the photoelectrochemical polymerization (PEP) process and the formation of the PEDOT capping layer. Larger pore sizes provided a more favourable pathway for the precursor diffusion through the mesoporous pores during the PEP process, which contributed towards a more efficient PEP. However, the interfacial contact area between the formed polymer and the dyes on the surface of TiO2 particle would be lower in the case of larger pore sizes, which consequently caused a less efficient dye regeneration process. Electronic diffusion on the other hand was improved for larger particle sizes. Employing an organic dye LEG4 and the self-made TiO2 with an optimal pore size of 25 nm and particle size of 24 nm, the sDSCs showed a promising power conversion efficiency (PCE) of 5.2%, higher than 4.5% for the commercial TiO2 Dyesol DSL-30. By measuring the dye regeneration yield and the kinetics through photoinduced absorption, it was observed that the homemade TiO2 based device had more efficient dye regeneration compared to the Dyesol based device, which could result from the better interfacial contact between the PEDOT and the dye. This work provides important information on the effect of meso-pore size on sDSCs and points to the necessity of further photoanode optimization toward the enhancement of the PCE of polymeric Hole Conductor-based DSCs.
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combining a small Hole Conductor molecule for efficient dye regeneration and a Hole conducting polymer in a solid state dye sensitized solar cell
Journal of Physical Chemistry C, 2012Co-Authors: Erik M. J. Johansson, Gerrit Boschloo, Licheng Sun, Lei Yang, Erik O Gabrielsson, Peter W Lohse, Anders HagfeldtAbstract:In dye-sensitized solar cells (DSC) an efficient transfer of dioles from the oxidized dye to the contact is necessary, which in solid-state DSC is performed by Hole-Conductor molecules. In this rep ...
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Comparison of charge accumulation and transport in nanostructured dye-sensitized solar cells with electrolyte or CuSCN as Hole Conductor
Solar Energy Materials and Solar Cells, 2005Co-Authors: Boriss Mahrov, Anders Hagfeldt, F.o. Lenzmann, Gerrit BoschlooAbstract:The charge transport properties of the dye-sensitized solar cells consisting of Ru(dcbpyH(2))(2)(NCS)(2)-sensitized nanostructured TiO2 with either redox electrolyte or CuSCN as Hole Conductor have ...
Erik M. J. Johansson - One of the best experts on this subject based on the ideXlab platform.
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in situ growth of perovskite stacking layers for high efficiency carbon based Hole Conductor free perovskite solar cells
Journal of Materials Chemistry, 2019Co-Authors: Jianhua Liu, Erik M. J. Johansson, Qisen Zhou, Nan Kyi Thein, Lei Tian, Donglin Jia, Xiaoliang ZhangAbstract:The interfacial properties between a perovskite layer and carbon electrode are critical for the photovoltaic performance of carbon electrode-based perovskite solar cells (PSCs). Herein, a methylammonium lead mixed halide (MAPbIxBr3−x) perovskite layer is in situ grown on the top of a methylammonium lead iodide (MAPbI3) perovskite layer forming a MAPbI3/MAPbIxBr3−x perovskite stacking structure (PSS) to improve the interfacial properties at the perovskite/carbon electrode interface. The charge carrier dynamics in both the perovskite and the PSC device induced by the MAPbIxBr3−x perovskite stacking layer are studied using extensive characterization. The charge interfacial recombination at the perovskite/carbon electrode interface is significantly diminished using the PSS within the PSC, resulting in largely improved charge extraction and therefore high photovoltaic performance. The PSS-based PSC shows a power conversion efficiency of up to 16.2% (increased by 43% compared with that of a conventional MAPbI3-based PSC), which is among the highest efficiencies of carbon electrode-based Hole Conductor free PSCs. Meanwhile, the PSS-based PSC also exhibits good stability under both continuous illumination and storage under dark conditions. This work may provide a new avenue to fine tune the interfacial properties of carbon electrode-based PSCs for further improving their photovoltaic performance.
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the effect of mesoporous tio2 pore size on the performance of solid state dye sensitized solar cells based on photoelectrochemically polymerized poly 3 4 ethylenedioxythiophene Hole Conductor
Electrochimica Acta, 2016Co-Authors: Jinbao Zhang, Erik M. J. Johansson, Meysam Pazoki, Justus Simiyu, Malin B Johansson, Ocean Cheung, Leif Haggman, Nick Vlachopoulos, Anders HagfeldtAbstract:Abstract Photoelectrochemical polymerization of poly(3,4-ethylenedioxythiphene) (PEDOT) has recently been introduced and widely investigated for fabrication of the Hole transporting material (HTM) in highly efficient solid state dye sensitized solar cells (sDSCs). In this work, the effects of the surface area and pore size of TiO2 film were for the first time investigated in the sDSCs employing the in-situ polymerizated PEDOT HTM. Three different varieties of mesoporous TiO2 particles with controllable surface area and pore size were synthesized through the basic route in order to study the corresponding sDSC photovoltaic performances. It was found that the pore size plays an important role in the kinetics of the photoelectrochemical polymerization (PEP) process and the formation of the PEDOT capping layer. Larger pore sizes provided a more favourable pathway for the precursor diffusion through the mesoporous pores during the PEP process, which contributed towards a more efficient PEP. However, the interfacial contact area between the formed polymer and the dyes on the surface of TiO2 particle would be lower in the case of larger pore sizes, which consequently caused a less efficient dye regeneration process. Electronic diffusion on the other hand was improved for larger particle sizes. Employing an organic dye LEG4 and the self-made TiO2 with an optimal pore size of 25 nm and particle size of 24 nm, the sDSCs showed a promising power conversion efficiency (PCE) of 5.2%, higher than 4.5% for the commercial TiO2 Dyesol DSL-30. By measuring the dye regeneration yield and the kinetics through photoinduced absorption, it was observed that the homemade TiO2 based device had more efficient dye regeneration compared to the Dyesol based device, which could result from the better interfacial contact between the PEDOT and the dye. This work provides important information on the effect of meso-pore size on sDSCs and points to the necessity of further photoanode optimization toward the enhancement of the PCE of polymeric Hole Conductor-based DSCs.
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combining a small Hole Conductor molecule for efficient dye regeneration and a Hole conducting polymer in a solid state dye sensitized solar cell
Journal of Physical Chemistry C, 2012Co-Authors: Erik M. J. Johansson, Gerrit Boschloo, Licheng Sun, Lei Yang, Erik O Gabrielsson, Peter W Lohse, Anders HagfeldtAbstract:In dye-sensitized solar cells (DSC) an efficient transfer of dioles from the oxidized dye to the contact is necessary, which in solid-state DSC is performed by Hole-Conductor molecules. In this rep ...
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Solid state dye-sensitized solar cells prepared by infiltrating a molten Hole Conductor into a mesoporous film at a temperature below 150 °C
Synthetic Metals, 2011Co-Authors: Kristofer Fredin, Erik M. J. Johansson, Maria Hahlin, Rebecka Schölin, Stefan Plogmaker, Erik Gabrielsson, Licheng Sun, Håkan RensmoAbstract:Infiltration of a molten Hole Conductor in a mesoporous film at an elevated temperature exhibits good wetting performance and the procedure is therefore suitable as part of the preparation method f ...
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PHOTOVOLTAIC AND INTERFACIAL PROPERTIES OF HETEROJUNCTIONS COMPRISING DYE-SENSITIZED DENSE TiO2 AND TRIARYLAMINE DERIVATIVES IN SOLID AND LIQUID STATE.
1996Co-Authors: Erik M. J. Johansson, Patrik G. Karlsson, Maria Hedlund, Declan Ryan, Hans SiegbahnAbstract:Different triarylamine derivatives have successfully been used as solid Hole-Conductor materials in dye-sensitized solar cells with efficiencies up to 4% [1-3]. In the present work TiO2/dye/ Hole-Conductor heterojunctions is assembled to form model systems for solid state DSSC and the interfacial structure at the molecular level. A series of triarylamine molecules is used to investigate the influence of small differences in the Hole-Conductor material structure on the photovoltaic and molecular surface properties. Both solid state and liquid state junctions with the triarylamine molecules were investigated. In the solid state heterojunctions the Hole-Conductor molecules were evaporated on the substrate and in the liquid state heterojunctions the Hole-Conductor molecules were solvated in an organic solvent. The photovoltaic properties of the heterojunction largely depend on the electron transfer rates at the interfaces between the different materials (semiConductor, dye and Hole-Conductor). Photoelectron Spectroscopy (PES) measurements was used to investigate the molecular and electronic interface structure. In the figure below the valence electronic structure of interfaces with the different Hole-Conductors are shown.From the valence PES the interaction and the energy level matching between the dyes and the Hole-Conductors is studied. The results show large differences in the energy matching of the different holconducting materials with respect to the dye molecules partly explaining the differences in efficiency. The valence structure also shows that when combining different materials their individual properties adjust slightly to their new environment. From the core level PES we observe differences molecular surface structure. Specifically it was found that the smaller Holecondctors are able to penetrate the dye layer and contact the TiO2 surface.