Preparation of Zr-doped mesoporous TiO2 particles and their applications in the novel working electrode of a dye-sensitized solar cell

This paper presents an implementation of our recent theory on the suspension of electron-hole recombination via electronic- and micro-structure optimization to study the influence of Zr-doping on the efficiency (η) of TiO₂-based dye-sensitized solar cells (DSSCs). We developed a four-layered working electrode, in which the size of particles increased from the bottom layer of TiO₂ (P-25) through three successive layers of Zr-doped TiO₂, which were calcined at 450, 600, and 850 °C respectively. The enhancement in open-circuit photovoltage (V_oc) and short-circuit photocurrent density (J_sc) can be attributed to the electronic- and micro-structures in the working electrode. The former is related to band bending, whereas the latter is related to light-scattering within multiple layers. Simulation results (FactSage) demonstrate that Zr doping in TiO₂ can suspend or delay the formation of oxygen vacancies and thereby reduce the number of electron scattering centers, which helps to suspend electron-hole recombination by strengthening Ti-O bonds. The proposed four-layered working electrode produced an 80.2% increase in η, compared with DSSCs using a TiO₂ (P-25) electrode. This study demonstrated a novel metal doping strategy for the manipulation of electronic structure and photoelectron conversion efficiency. The proposed methodology could also be used to guide the design of photo-catalysts in general.     

Synergistic catalytic effect of a composite (CoS/PEDOT:PSS) counter electrode on triiodide reduction in dye-sensitized solar cells

Inorganic/organic nanocomposite counter electrodes comprised of sheetlike CoS nanoparticles dispersed in polystyrenesulfonate-doped poly(3,4-ethylenedioxythiophene (CoS/PEDOT:PSS) offer a synergistic effect on catalytic performance toward the reduction of triiodide for dye-sensitized solar cells (DSSCs), yielding 5.4% power conversion efficiency, which is comparable to that of the conventional platinum counter electrode (6.1%). The electrochemical impedance spectroscopy (EIS) and cyclic voltammetry measurements revealed that the composite counter electrodes exhibited better catalytic activity, fostering rate of triiodide reduction, than that of pristine PEDOT: PSS electrode. The simple preparation of composite (CoS/PEDOT:PSS) electrode at low temperature with improved electrocatalytic properties are feasible to apply in flexible substrates, which is at most urgency for developing novel counter electrodes for lightweight flexible solar cells.     

Preparation of conducting polyanilines doped with Keggin-type polyoxometalates and their application as counter electrode in dye-sensitized solar cells

Conducting polyanilines doped with two Keggin-type polyoxometalates (POMs) were synthesized by chemical oxidation of aniline. Both conducting polymers provided electrical conductivity values up to 0.1 S cm⁻¹, as measured by the standard four-probe technique. Structural and morphological characterizations for these materials were achieved by FTIR spectra, X-ray diffraction, scanning electron microscopy (SEM), and thermogravimetric analysis. These conducting polyanilines doped with Keggin-type polyoxometalates (PANI–POMs) were also used to prepare a new type of counter electrode for application in dye-sensitized solar cells (DSCs). Promising results were achieved from DSCs based on PANI–POMs as the materials for the counter electrode, which provides evidence for the dopant role in enhancing the electrical conductivity of PANI.     

Conductive polymer PEDOT:PSS back contact for CdTe solar cell

Two types of superstrate glass/ITO/CdS/CdTe PV structures were prepared by high vacuum evaporation technique with (i) activation of CdS layer and CdS/CdTe bi-layer structure step-by-step and (ii) activation of CdS/CdTe bi-layer structure. The activation was performed by annealing the structures with CdCl₂ in air at 400 °C for 15 min. Main conditions for CdS and CdTe thin films deposition and following treatment were selected from the literature data with the purpose to prepare and compare complete CdTe solar cells with standard p + Cu_xTe back contact and conductive polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS) back contact. Obtained layers and structures were characterized using the XRD, SEM and I-V methods. Both the methods of activation treatment give comparable results from the point of view PV properties of complete solar cells. It was found that highly conductive PEDOT:PSS intermediate layer can significantly improve the back contact characteristics of CdTe. However these hybrid structures need to be further optimized to compete successfully with conventional inorganic back contacts in complete CdTe solar cells.     

表面活性剂改性的大孔径介孔炭对电极染料敏化太阳电池(英文)

以大孔径的介孔炭(MC)为催化层材料经低温热处理构建出炭对电极,着重探讨了在炭浆料中添加Triton X100对其组装的染料敏化太阳电池(DSCs)光电性能的影响,并引入分形维数(DF)用于定量评估炭膜形貌的差异。结果表明,当炭浆料中Triton X100的含量增加到0.1 mL(相应MC含量为0.6 g)时,DSCs的光电转换效率增加至5.65%,其值比活性炭对电极DSCs高46.5%,且达到Pt对电极DSCs的95.4%。Triton X100改性的介孔炭对电极的高性能归功于高品质的炭膜和介孔炭本身合理的孔结构(如大尺寸孔径和大比表面积等)。相对于未添加Triton X100的纯介孔炭对电极,Triton X100改性的介孔炭对电极具有分布更均匀的炭膜和更小的分形维数,是对电极欧姆串阻减小及相应器件效率改善的一个重要因素。     

Sub-micrometer-sized graphite as a conducting and catalytic counter electrode for dye-sensitized solar cells

Sub-micrometer-sized colloidal graphite (CG) was tested as a conducting electrode to replace transparent conducting oxide (TCO) electrodes and as a catalytic material to replace platinum (Pt) for I(3)(-) reduction in dye-sensitized solar cell (DSSC). CG paste was used to make a film via the doctor-blade process. The 9 μm thick CG film showed a lower resistivity (7 Ω/?) than the widely used fluorine-doped tin oxide TCO (8-15 Ω/?). The catalytic activity of this graphite film was measured and compared with the corresponding properties of Pt. Cyclic voltammetry and electrochemical impedance spectroscopy studies clearly showed a decrease in the charge transfer resistance with the increase in the thickness of the graphite layer from 3 to 9 μm. Under 1 sun illumination (100 mW cm(-2), AM 1.5), DSSCs with submicrometer-sized graphite as a catalyst on fluorine-doped tin oxide TCO showed an energy conversion efficiency greater than 6.0%, comparable to the conversion efficiency of Pt. DSSCs with a graphite counter electrode (CE) on TCO-free bare glass showed an energy conversion efficiency greater than 5.0%, which demonstrated that the graphite layer could be used both as a conducting layer and as a catalytic layer.     

Preparation of Cu3SnS4 film with single ceramic target magnetron sputtering for Pt-free counter electrode of dye-sensitized solar cell

Journal of Materials Science: Materials in Electronics - Cu3SnS4 (CTS) films were successfully prepared on FTO glass via DC magnetron sputtering by using a single ceramic target. The CTS/FTO glass...     

磁控溅射制备染料敏化太阳能电池氮掺杂碳膜对电极

采用双极脉冲磁控溅射法制备氮掺杂碳膜并作为对电极应用在染料敏化太阳能电池(DSSC)中。研究了氮掺杂对碳膜的结构与性能的影响。用X射线光电子能谱(XPS)对氮掺杂碳膜进行薄膜表面元素分析,用四探针测试仪对氮掺杂碳膜的方块电阻进行测试,用扫描电镜对氮掺杂碳膜表面形貌进行分析。组装电池,用太阳光模拟器测试电池的光电转化率。研究结果表明,经过氮掺杂的碳膜,表面形貌致密,当N2的体积分数为30%时,薄膜中N元素含量为15.21%,薄膜的方块电阻为9.4Ω/□,电池的光电转化率为1.16%。     

PEDOT:PSS as back contact for CdTe solar cells and the effect of PEDOT:PSS conductivity on device performance

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was studied as the back contact of Cadmium telluride (CdTe) solar cells and was compared with conventional Cu-based back contact. A series of PEDOT:PSS aqueous solutions with different conductivities were spin coated onto the glass/SnO2:F/SnO2/CdS/CdTe structures as back contact, and the PEDOT:PSS conductivity dependence of device performance was studied. It was found that PEDOT:PSS back contact with higher conductivity produces devices with lower series resistance and higher shunt resistance, leading to higher fill factor and higher device efficiencies. As the conductivity of PEDOT:PSS increased from 0.03 to 0.24 S/cm, the efficiency of the solar cell increased from 2.7 to 5.1 %. Methanol cleaning also played an important role in increasing the device performance. The efficiency of our best device with PEDOT:PSS back contact has reached 9.1 %, approaching those with conventional Cu/Au back contact (12.5 %).     

High-efficiency dye-sensitized solar cell based on a nitrogen-doped nanostructured titania electrode

A highly efficient dye-sensitized solar cell (DSC) was fabricated using a nanocrystalline nitrogen-doped titania electrode. The properties of the nitrogen-doped titania powder, film, and solar cell were investigated. The substitution of oxygen sites with nitrogen atoms in the titania structure was confirmed by X-ray photoemission spectroscopy (XPS). The UV-vis spectrum of the nitrogen-doped powder and film showed a visible light absorption in the wavelength range from 400 to 535 nm. An enhancement of the incident photon-to-current conversion efficiency (IPCE) in the range of 380-520 nm and 550-750 nm was observed. An 8% overall conversion efficiency has been achieved. The results of the stability test indicated that the solar cell fabricated by the nitrogen-doped titania exhibited great stability.     

Improvement of organic solar cell efficiency by solution-processed doping of pentacene in PEDOT:PSS layer

In the current research, organic solar cells (OSCs) with various concentrations of pentacene in Poly(ethylenedioxythiopene):Poly(styrenesulfonate) (PEDOT:PSS) interface layer were investigated for better hole extraction. The ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al-fabricated solar cell fabricated via brush coating provides superior photovoltaic, electrical and optical characteristics when compared with the ITO/PEDOT:PSS/P3HT:PCBM/Al solar cell. The ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al solar cells deliver a V_OC ~350?mV and 2.57% efficiency. It is observed that the optimized concentration of pentacene doping in PEDOT:PSS layer, along with an active layer of P3HT and PC₆₀BM, doubles the efficiency of the device, when compared with pristine PEDOT:PSS layer. The degradation studies of the fabricated bulk heterojunction OSCs reveal that the degrading abilities of ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al solar cells are 60% more better than those of ITO/PEDOT:PSS/P3HT:PCBM/Al devices. Thus, this work will ultimately contribute toward fully solution processed painted device, which will provide low-cost manufacturing and improved stability of pentacene-based organic photovoltaics.     

生物质衍生没食子酸增强PEDOT:PSS膜导电性能及其调控机制

聚3, 4-乙烯二氧噻吩(PEDOT)因其具有柔性可拉伸、生物相容性高、导电及功函数可调控等优势在柔性可穿戴电子器件中显示出广阔的应用前景。近年来,随着资源危机的日益凸显,针对PEDOT:聚苯乙烯磺酸(PSS)体系,研究开发高效绿色可持续的生物质基掺杂剂,已引起相关研发人员的高度关注。本研究首次报道了采用生物质芳香弱酸?没食子酸(GA,pKa为4.41)掺杂制备高性能PEDOT导电膜的新途径。GA独特的邻多酚羟基结构创造了稳定的GA-PSSH双氢键,使得GA-PSSH的分子结合能显著高于GA的石油基强酸异构体(2, 4, 6-三羟基苯甲酸,pKa=1.68)与PSSH的分子结合能。GA掺杂不仅可实现PEDOT-PSS的高效相分离,而且优化了PEDOT分子链的构象、聚集结构的形貌及其排列方向。这赋予GA具有很高的掺杂效率,当GA掺杂量为1.2%时,PEDOT导电膜的电导率可提升三个数量级,达到1050 S/cm,导电性能达到已报道的生物质基掺杂剂的最高水平,且掺杂效率明显优于其它生物质基掺杂剂及其石油基强酸异构体。      

Ultralight conducting PEDOT: PSS/ Carbon Nanotubes Aerogels Doped with Silver for Thermoelectric Materials

正Significant enhancement of thermoelectric per-formance was observed for Poly(3,4-ethylene-dioxythiophene):Poly(4-styrenesulfonic)(PEDOT:PSS)and multi-walled carbon nanotubes(MWCNTs)(PC)three-dimensional aerogelswhich were obtained from PEDOT:PSS/MWCNTssuspensions by adding different concentrations of     

染料敏化太阳能电池MO／TiO2复合薄膜的制备与表征

用溶胶-凝胶法结合旋转镀膜法制备致密TiO2薄膜，采用丝网印刷技术制备多孔TiO2薄膜，采用液相沉积法制备ZnO／Ti02、MgO／TiO2复合薄膜。用x射线能谱仪、原子力显微镜、紫外-可见分光光度计对复合薄膜的化学组分、表面形貌、吸光性能等进行分析；组装电池，测定了电池性能。结果表明：ZnO／TiO2、MgO／TiO2复合薄膜具有较好的光电性能，染料敏化太阳能电池的短路电流、开路电压、填充因子、光电转换效率均得到提高。     

Conductivity enhancement of PEDOT:PSS thin film using roll to plate technique and its characterization as a Schottky diode

The conductivity of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) was improved by pressing the PEDOT:PSS thin film using roll to plate system. PEDOT:PSS thin film was deposited on polyethylene terephthalate using electrohydrodynamics atomization technique. The physico-chemical properties of the pressed thin film at different loads were compared with an un-pressed sample. The electrical properties show that the film conductivity has been increased by four times. An optimized pressing load was found to have good conductivity and transmittance of the thin film. A hybrid device (PEDOT:PSS/F8BT/ZnO/Ag) was fabricated using layer by layer method with PEDOT:PSS as anode. The I–V characterization showed that the device with pressed PEDOT:PSS showed higher current densities. The results give a promising future of PEDOT:PSS in electronics device applications using printed electronics techniques.     

Efficiency enhancement of polymer solar cells with Ag nanoparticles incorporated into PEDOT:PSS layer

In this study, large-sized silver nanoparticles (Ag NPs) (average size: 80 nm) have been introduced into the anodic buffer poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer (thickness: about 55 nm) of poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester bulk heterojunction polymer solar cells. The results showed that the short-circuit current density can increase from 8.73 to 11.36 mA/cm², and power conversion efficiency increases from 2.28 to 2.65 % when 0.1 wt% Ag NPs was incorporated in PEDOT:PSS layer, corresponding to an efficiency improvement of 16.2 %. Absorption spectrums of the active layers indicate that large-sized Ag NPs have no clear contribution to optical absorption improvement. By measuring the conductivity of PEDOT:PSS films without and with Ag NPs and analyzing device structure of this polymer solar cell, it was founded that the improvements in power conversion efficiency was originated from higher conductivity of PEDOT:PSS layer incorporated with Ag NPs and the shorter routes for holes to travel to the anode.