In this presentation, I’ll give an introduction to the “NRC Printable Electronics Flagship Program” and review the technologies for organic photovoltaics and printed transistors. The achievements for the development of organic photovoltaics at NRC will be presented and discuss the challenges ahead for commercialization. The different printing techniques will be presented to address the difficulties of printing process instead of spin coating process in the lab. The development of inkjet-printed PMOS inverters and logic gates on flexible substrates will be presented. The manufacturing yield of 97% of inkjet-printed OTFTs has been demonstrated. Optimized enhancement-load PMOS inverters on PET substrate obtained a high voltage gain up to 11 v/v.

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The performance improvement of InGaP/InGaAs dual-junction solar cells with an ITO transparent electrode was explored. It is found the ITO electrode can not only play the transparent electrode, but also be used as an anti-reflection layer resulting in increasing the absorption efficiency of the visible light.

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In this study, the absorption coefficient and refractive index of a tri-iodide perovskite absorber (TPA) was obtained by fitting the transmittance spectra of TPA/ PEDOT: PSS/ITO/glass using the transfer matrix method. The 3-D FDTD method was used to design a 2-D periodic Cu nanoplasmonic structure to enhance the exciton generation at the interface between TPA and Cu nanoparticles. Base on this method the thickness of the TPA film can be reduced with the same absorption property.

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In this work, we have successfully demonstrated the great advantage of plasmonic Au nanoparticles for efficiency enhancement of CIGS flexible photovoltaic devices. The enhancement of external quantum efficiency(EQE) and photocurrent have been systematically analyzed by simulation and experiments.

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The silicate phosphor on the surface of GaAs solar cell are demonstrated to have promising potential for efficient solar spectrum utilization. The solar cells showed an enhancement of 22.8% in short-circuit current density and approximately 25.3% in power conversion efficiency when coated with silicate phosphor particles.

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This project plans to understand the relation between Electroluminescence (EL) images and the defect structure of solar cells. Up to now, the PV industry hasn’t found any rapid and effective ways to identify the microcracks on multi-crystalline silicon (mc-Si) solar cells, just as they did to single-crystal silicon solar cells. By observing the change of EL images of the mc-Si solar cells during an aging test, we hope to clarify how the aging process and the defects of solar cells/modules influence the EL images and the electric power output. We applied different image processing methods of EL images to identify the location of the defects structures. Our goal is to develop an automatic identification program. The experimental results show that the variations of the grayscale levels of the EL images were small and located within the predicted range. That means the cells’ efficiency was not affected by the aging test. We colorized certain grayscale level values in red and into four colors or 16 colors. Both methods allowed the rough distinguishing of high and low efficient areas. However, specific defects such as cracks could not be identified by these methods. A semi-automatic colorization method was successfully used to increase the interpretation accuracy of the EL images although there were still some drawbacks. In the near future, we intend to apply blocks algorithm to automatic colorization of the EL images.

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We practically measured the charging efficiency of greater than 85% by using a 100×30 cm2 plastic CIGS solar panel to offer the electrical power injected into the lithium battery. However, this high charging efficiency is depended on the remaindering power of the battery. The high charging efficiency of 85% can be obtained at the initial empty battery. As prolonged the charging time, the charging efficiency is going decreased.

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Graphene oxide/Pt composite counter electrodes (CEs) are prepared for dye-sensitized solar cells (DSCs). The composite CE provides a higher efficiency of reaction of redox couple. Based on this approach, the DSCs with a lower loading of Pt CEs can be achieved.

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We reported a chemical treatment which could passivate the defects of CuIn1-xGaxSe2 (CIGS) film by immersing the thin film in trioctylphosphine sulfide (TOP:S) solution. By means of photoluminescence (PL) measurements, PL intensity of CIGS thin film increased with TOP:S passivation.

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in this work, we demonstrated an organic solar cell with C60/ boron subphthalocyanine (SubPc) (acceptor/donor) inverted structure. Electrical and optical characteristics were demonstrated with different thicknesses of molybdenum trioxide (MoO3) hole-extracting layer.

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Chemical bath deposition was employed to deposit Cu2ZnSnS4 (CZTS) films, which were sulfurized by ditert-butylsulfide (DTBS) in an atmospheric pressure quartz reactor at 400~600°C. Increments of sulfurization time interval or DTBS admittance enable the formation of CZTS structure. The characteristics of CZTS under various sulfurization conditions are addressed.

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In this report, we demonstrate the relationship between charge transfer states and open-circuit voltage (VOC) in small-molecule organic photovoltaic devices. It is found that the VOC not only depends on the interface gap between donor and acceptor but also the injection property and donor/acceptor interfacial area.

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By stacking InGaAs quantum dots layers of different compositions, we can increase the broadband absorption range near photon energy = 1eV. The broadband quantum dots solar cell consists of consists of 3 different QDs, and each QD has 3 layers. The short circuit current is improved about 124% by the growth of ZnO nanorods array on the surface of solar cell.

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ZnO nanorods were synthesized by a two-step approach in this study. The ZnO films as a seed layer were deposited on the glass by sol-gel. The ZnO nano-particle seed solution was spin coated onto FTO glass substrates.Different morphologies of ZnO nanorods demonstrated by different growth time.efficiency of 0.347% were obtained.

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The H2 plasma passivation was used to improve the efficiency of amorphous silicon (a-Si) solar cells. The efficiency of H2 plasma-passivated a-Si solar cells fabricated on glass substrate increased to 4.22 %. Finally, the a-Si solar cell with efficiency of 3.27 % was successfully fabricated on plastic substrate.

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This study proposes the inorganic phosphor used in the luminescent solar concentrator (LSC) for the luminescent material. It was found that the re-emitting light escaping from the escape cone would be a serious problem for the use of LSC and should be solved. It was also found that the re-emitting light escaped from the rear surface more than the light from the side surfaces.

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We demonstrate a promising structure and key factors to achieve high-efficiency hybrid heterojunction solar cells, which can facilitate the device performance. By using the multi-textured pyramid/silicon nanowire (SiNW) to achieve low reflection and designing hole-transporting layer (HTL), the device performance is enhanced to 11.5%.

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A new cathode buffer layer is developed for the use in organic photovoltaic devices. Besides the thickness-independent electrical effects, the injection efficiency is also increased. The window of thickness tuning of this new cathode buffer is in a range of 8-24 nm, indicating the potential use in optical spacer.

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The anti-reflection behavior of multilayer polyelectrolyte on thin film solar cell is investigated. The cationic and anionic polyelectrolyte deposited with layer by layer self-assembly method proved effective in enhancing the anti-reflectivity and quantum efficiency of the thin film solar cell.

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Coating profiles of PEDOT:PSS on Si nanowires (SiNWs) are improved by Zonyl fluorosurfactant treated PEDOT:PSS. After treatment, SiNW/PEDOT:PSS solar cells generate higher PCE of 10.87%, Jsc of 28.86 mA/cm2, and FF of 71.75%. Comparatively, the control devices have lower PCE of 9.55%, Jsc of 28.04 mA/cm2, and FF of 63.57%.

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In this research, we use two-step process to form perovskite CH3NH3PbI3 on planar ZnO thin layer. The whole process is completed under low temperature. The best device has high Jsc of 20 mA/cm2 and efficiency of 13.3% due to uniform morphology of ZnO film and appropriate control of two-step process.

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In this report, we composite PEDOT:PSS and carbon black as counter electrodes to replace the conventional platinum electrodes in DSSCs. By controlling the thickness of PEDOT:PSS film, JSC were increase obviously. After mixed PEDOT:PSS with carbon black, the fill-factor and thus the device efficiency were improved in further.

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To obtain high-quality In0.16Ga0.84As epitaxial films, we designed the step graded or linear graded buffer layer on the GaAs substrate before growing the InGaAs epilayer. The conversion efficiencies of In0.16Ga0.84As solar cells with step graded and linear graded buffer layers were measured to 14.8% and 16.6%, respectively.

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In this work, we study the lifetime of dye sensitized solar cells (DSSCs). The performances of the device under air atmosphere were measured and discussed. The device performances could be recovered partially after re-injecting the electrolyte. The un-reversible part of device efficiency could be attributed to degradation of the dye.

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In this project, an advanced solar simulator was developed. The superior properties of the simulator can meet the requirements of production lines of new generation photovoltaic (PV) modules. It is expected to take the place of existing products on the market. By using the light propagation and flexibility of optical fibers, the energy of light source is distributed onto the illuminated area uniformly, enabling the flash solar simulator to test efficiency of PV modules on production lines. On the illuminated area of 2m x 1.5m, the irradiance is needed to be at least 1000W/m2. Spectral match, non-uniformity, and temporal instability of the simulator are better than the definition of A class by IEC60904-9. Especially, the spectrum matches AM1.5G from 300nm, making the testing results of PV modules more actual and precise. A high speed IV tracer was also developed in this project. The IV tracer can perform IV curve measurements within a pulse (10ms), and parameters such as Pmax, Isc, and F.F. are figured out as well.

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This article is to study how the electrochemical deposition of copper oxide deposit as a solar cell applications, and the only way to explain this is deduced special IV Solar energy level graph model.

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We use wet etching method to improve the light absorption of GaAs hybrid solar cell. The weighted reflectance decreases to 12.75% and PCE can achieve 9.8%. According to photon recycling model, conducting wafer lift-off process and place back reflector which can improve Voc by 0.04V .

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Metal-assisted chemical etching is a wet etching method that produces anisotropic high aspect ratio. The diameter and length of Si nanowires could be precisely controlled. Here we use MacEtch to fabricate our devices, the short-circuit current was enhanced to 34.0mA/cm2, with the power conversion efficiency of 11.9%.

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We demonstrate an 980-nm laser-driven CMOSenabled interdigitated back-contact (IBC) solar cell for biomedical applications. The design of this device leverages from the CMOS process to allow two-dimensional junction formation and uniform series resistance, but suffers from poor minority carrier properties in bulk substrate. This issue is partially solved in this work by thinning down the substrate to 60 m, leading to an ultimate efficiency of 15%. After inserting an emulated tissue loss, a 1.67 mm2 IBC solar cell is capable of generating an electrical power of 159 W under a concentrated illumination intensity of 10 mW, which is within the conservative limit to human skin.

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Graphene oxide (GO) is prepared to be the alternative hole transport layers (HTLs) for polymer solar cells (PSCs). The thickness of GO-HTLs are optimized. The PSC with 2-nm UV-treated GO HTL has a higher hole collection efficiency, resulting a compatible photovoltaic performance to a conventional PSC with PEDOT:PSS HTL.

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Conducting polymers, such as PEDOT:PSS, have been considered as one possible replacement of Pt as more cost-effective counter electrodes in DSSCs. However, earlier attempts in replacing Pt counter electrodes with PEDOT:PSS mostly resulted in substantially degraded DSSC efficiencies, due to poorer conductivity and electrochemical activity of PEDOT:PSS. Taking advantage of the development of high-conductivity PEDOT:PSS in recent years, in this work we report the preparation of high-conductivity PEDOT:PSS (up to ~1000 -cm) and its application as counter electrodes to achieve DSSC efficiencies (>9%) comparable to those achieved with Pt electrodes.

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30-period Type-II 5 ML InAs/5 ML GaSb superlattice Infrared photo-diodes are investigated. The device has exhibited a 4.25 m cut-off wavelength at 10K. With an additional 1 ML InSb layer grown between GaSb/InAs interfaces, compressive-strained SLs are obtained, which provide a possibility of strain-compensated InAs/GaSb SL structure.

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In this study, 5% and 10% Co-doped BFO multiferroic ceramics were synthesized by solid state reaction (SSR) method with various sintering temperature. They present single phase in XRD measurements. The average grain size of Co-doped BFO grows significantly with increasing sintering temperature as observed by SEM. Increasing Co content of BFO makes the grains to a rectangle shape and enhances the ferromagnetic behavior at room temperature.

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Abstract-In recent years, the perovskite solar cells is a advancing photovoltaic devices. The power conversion efficiency of perovskite solar cells has been gradually increased. This paper discusses DSSCs with perovskite and photovoltaic performances. The perovskite CH3NH3PbI3 is deposited on the TiO2 layer of DSSCs via spin coating. Using the fabrication of perovskite solar cells increases power conversion efficiency.

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In this study, a sub-wavelength structure (SWS) on silicon(Si) solar cells using the rigorous coupled-wave analysis(RCWA) method is presented. Various SWS of different shapes and period are discussed in detail. The optimized reflectance is under 1% during 500-600nm incident wavelength and enhancement is 47%.

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We studied the effect of negative bias on deposition of TiO2 on ZnO in the electrochemical deposition process for the preparation of anodes of dye-sensitized solar cells. We found that oxygen vacancies at ZnO/TiO2 interface, thickness of TiO2 layer, and Ti4+/Ti3+ ratio are 3 major factors affecting the performance.

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In this study, graphene nanosheets-Pt stacked counter electrodes were characterized and used to fabricate DSSCs. The Jsc, Voc, and fill factor of the DSSC based on conventional Pt counter electrode are 14.56 mA/cm2, 0.70 V and 0.70, respectively, yielding an overall efficiency of 7.13%. The DSSC based on graphene nanosheets-Pt stacked counter electrodes showed an enhanced efficiency of 8.16%. Power conversion efficiency of the DSSC was enhanced by ~14% with using the graphene nanosheets-Pt stacked counter electrodes.

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We analysis the coupling QD structure advantages in forming intermediate band. In structure design, we convinced that the coupling QD structure will help to broaden the bandwidth of intermediate band. The results revealed that the GaAsSb thickness equal to 5.5 nm with Sb concentration 0.12 will help in IBSC design.

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In this work, high density silicon nanohole (SiNH) arrays were fabricated on n-type wafer by using simple solution process two-step metal-assisted chemical etching method. SiNHs exhibit very low reflectance from range of wavelength 300 to 1100 nm irrespective of the angle of incidence. Si/PEDOT:PSS hybrid solar cells exhibit high Jsc of 36.80 mA/cm2, voc of 0.52V, FF of 66.50%, and thus power conversion efficiency (PCE) of 12.72%.

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Recently, tin sulfide (SnS) has been demonstrated to be a potential photovoltaic absorber for the future thin film solar cells due to high absorption coefficient (~105 cm-1) and the bandgap of 1.3eV. In order to study the solar performance, the buffer layer of CdS and ZnS and the window layer of FTO, ITO and ZnO for using in SnS thin film solar cells are simulated by the AMPS-1D simulation software in this work. It is observed that the SnS solar cells with a ZnO/ZnS/SnS layer structure exhibit higher solar efficiency than that with a ZnO/CdS/SnS layer structure, owing to less buffer layer absorption and good conduction band alignment. In addition, the SnS solar cells with the layer structures of FTO/SnS, ZnO/SnS and ZnO/ZnS/SnS demonstrate higher efficiency, open circuit voltage and short circuit current than that with the structure of ITO/SnS and ZnO/CdS/SnS.

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In this work, Electrolyte mixed with PVDF-HFP and P25 particle was used as quasi-solid electrolyte for the flexible dye-sensitized solar cells (DSSCs). The effects of quasi-solid electrolyte on the performance of the DSSCs have been investigated in this work. The TiO2 particles added in the quasi-solid electrolyte can improve the photovoltaic conversion efficiency of the DSSCs. The flexible DSSCs with quasi-solid electrolyte have achieved photovoltaic conversion efficiency as high as 1.17%.

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We introduce the use of low temperature sputtered NiOx thin film and solution-processed NiOx as an effective electron blocking layer for mesoscopic NiO/CH3NH3PbI3 perovskite solar cells. The cell efficiency has been improved from 9.511 to 10.7% for devices using NiOx fabricated under pure argon atmosphere. With adequate doping under 10% oxygen flow ratio, we achieved power conversion efficiency of 11.6%.

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The performances of P3HT:PC61BM solar cells are studied experimentally and theoretically. The absorption spectra for those with different thicknesses are simulated by RCWA method and compared with the experimental results. The power conversion efficiency of the polymer solar cell can reach 3.34%.

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The optical constants of the measurement conditions for different packages of the ethylene-vinyl acetate, in a non-destructive way to monitor the reliability of photovoltaic module encapsulation.

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A planar solar concentrator consisting of one planar substrate is proposed. The grooves scratched on the bottom side of this concentrator reflect the incident sunlight to both side walls of the concentrator. To evaluate the performance of the proposed planar concentrator, the optical properties of concentrator are simulated and analyzed.

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A method based on the transmission line model is applied to investigate the contact resistivity of the electrode in the solar cell herein. Meanwhile, an additional pad between the transparent electrode, such as graphene, and the substrate is proposed to reduce the contact resistance and then enhance the efficiency.

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From EIS measurement, we identify 2 distinct synchronized frequencies corresponding to 2 charge transfer mechanisms in the dye-sensitized solar cells, by varying the anode thickness and the applied voltage. The identification is critical in confirmation of corresponding mechanisms as a result of any improvement attempt of the solar cells.

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Linear and hyperbranched polythiophene derivatives containing diketopyrrolopyrrole (DPP) as linking groups were synthesized. Thermal stabilities of polymers were enhanced by introducing DPP groups, while their energy levels were also modified. All polymers were used as active layers for fabrication of inverted solar cell devices.

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To accurate characterization of DSC requires different level lighting consideration on each very slow temporal response. Good accuracy data showed measurement shall be real time removing capacitance effect with a Real-Time One-Sweep Method (RTOSM), which is useful to measuring cell more accurately and rapidly when evaluating performance.

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Potential Induced Degradation (PID) is a serious PV reliability issue it caused the PV module power loss and lifetime degradation. In this paper a new module structure design can help to achieve high reliability and without PID issue PV module products.

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In this study, reduced graphene oxide counter electrodes for dye-sensitized solar cells processed by atmosphere pressure plasma jets are presented. The best achieved power conversion is ~5.19%, which is comparable to that of the reference cell using a reduced graphene oxide counter electrode processed with a conventional furnace. This new methodology greatly reduces the processing time from 15 min to 11 s and consumes only about 1/3 of the thermal budget per unit area in comparison with the conventional furnace calcination process.

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Shallow trenches corresponding to metal contact area are first formed by screen-printing and chemical etching, followed by heavy doping over the whole front surface of the silicon wafer. The heavy doping remains at the shallow trench area while other areas become lightly doped through an etch-back method.

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We present the structure, optical and mechanical properties of PEDOT:PSS films. The local conductivity of the PEDOT can be obtained by fitting the transmittance spectrum with transfer matrix method. The PEDOT:PSS film was used as an anode for P3HT:PCBM based photovoltaics, resulting in a power conversion efficiency of 3.28 %.

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We design a selective filter to confines the re-emitted photons from radiative recombination, and use Shockley-Queisser detailed balance model to calculate Voc. According to the results of simulation, we design the varied cutoff wavelength of selective filter on our devices. The Voc of InGaP solar cells has 1.5 mV enhancement with 650 nm cutoff wavelength filter.

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A broad organic-inorganic series of metal iodide perovskites with the general formulation ABI3, where A is the CH3NH3 and B is Sn, Pb and Sn/Pb composite are reported. The compounds have been prepared through a variety of synthetic approaches, and the nature of the resulting materials is discussed in terms of their and optical properties.

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In this paper, the indium-tin-oxide (ITO) and Ti-doped GaZnO (GTZO) quaternary alloys were used as the transparent conductive oxides (TCOs) for Cu(In,Ga)Se2 (CIGS) solar cell application. The results indicated that GTZO thin films showed a high transmittance of 85.6%, and a low thin-film resistivity of 5.47×10-4 Ω-cm. The CIGS solar cells with high-performance GTZO TCOs exhibited an improved conversion efficiency of 8.2 %, which was higher than that with ITO TCOs (7.4 %). The improved device performances in this study demonstrated a high potential for developing high-performance CIGS solar cells by using GTZO TCOs.

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Application of optical emission spectroscopy (OES) to observe the stability of the chamber condition. We report the film properties of intrinsic a-Si:H passivation layers deposited with various film thickness that deposited by RF (13.56 MHz) PECVD and optimizing the passivation quality after anneal process.

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To explore the application of the sub-micro particles of graphite(SMG) and micro particles of graphite(MG) at counter electrode(CE) in dye-sensitized solar cells(DSSCs).The results show that the efficiency of DSSCs with SMG counter electrode, 2.36% higher then that of MG CE, 2.07%,and it's attributed to the particle size of SMG is smaller than MG particle.

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The TiO2 compact layer was introduced to photoanode in dye-sensitized solar cells (DSSCs) to enhance the current density and photoelectric conversion efficiency. In this study, when the thickness of TiO2 compact layer was increased, the current density and photoelectric conversion efficiency are improved by 51% and 58%, respectively.

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The charge collection probability is one of the important quantity in a solar cell. We use two special functions to fit the quantum efficiency of a GaAs Solar cell and differentiate them and use the combination of these derivatives to approximate the charge collection probability.

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InGaN-based solar cells with three types of action regions are characterized: multiple quantum wells (MQW), single junction, and the junction with graded indium composition. Despite her largest fill factor, the device with graded junction exhibits lower conversion efficiency than that of MQW structure, which is attributed to insufficient carrier collection.

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This study prepares a structure that can improve dye-sensitized solar cells (DSSCs) efficiency which used graphene and sandwich compound structure can enhance electronic transmission and electron conversion efficiency. When used this structure, the open circuit voltage(Voc) can increase from 0.54V to 0.6V and the fill factor (F.F) can increase from 0.565 to 0.585. Therefore, the efficiency can increase 62.6%.

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