NH_4I界面修饰SnO_2的平面钙钛矿太阳能电池的性能研究

近年来,钙钛矿太阳能电池(PSCs)受到研究者的广大关注,其光电转换效率(PCE)在短短十年间已经从原先的3.8%提升至25.5%。高效率的PSCs往往需要昂贵的空穴传输层以及金电极,并且其存在着较多的界面缺陷问题,所以无空穴传输层的碳对电极的PSCs受到了广泛的关注。其中电子传输层的自身的界面缺陷影响了器件的稳定性以及光电性能。本工作将采用碘化铵界面修饰的方法减少氧化锡电子传输层的界面氧空位缺陷。结果表明碘化铵的界面修饰对钙钛矿薄膜形貌生长有益。碘化铵界面修饰时,平面碳对电极钙钛矿太阳能电池的效率从12.450%提升到了13.772%。     

ZnO基光电极的构筑及其光电催化水分解性能研究进展

光电催化水分解制取氢气是最理想的制氢技术之一。光电极材料作为光电催化水分解反应系统最核心的部分,决定着太阳能到化学能的转换效率。氧化锌（ZnO）半导体因具有较低的超电势、高的电子迁移速率和价格低廉等优点,引起了广泛关注。然而,ZnO半导体的禁带较宽、电子-空穴易于复合和表面水氧化反应动力学缓慢,阻碍了其高效利用太阳能和实现理论效率。本文从ZnO的微纳结构和表界面修饰两个方面出发,综述了近年来ZnO基光电极的构筑策略及其光电催化性能的研究进展。首先阐述了ZnO的微观形貌和缺陷对光电性质的影响。然后总结了元素掺杂、量子点敏化、贵金属沉积、异质结构造和共催化剂沉积等策略对ZnO基半导体的表界面的构筑及对光电催化性能的影响。最后对未来高效ZnO基半导体光电极研究方向进行了展望,具体包括5个方面：ZnO表面改性;在原子水平构筑复合半导体催化剂的相界面;用廉价双金属或多金属纳米颗粒取代纯贵金属Au、Ag和Pt纳米颗粒;构建高效的电催化剂助剂;在ZnO半导体和助剂界面引入空穴储存层或电子堵塞层。     

全无机纳米晶太阳能电池的研究进展

近年来,以胶体纳米晶半导体材料作为构建部分的第三代太阳能电池（又称为量子点太阳能电池）一直是研究的热门课题。胶体量子点在太阳能电池中应用之所以备受关注,是由于其具有类似溶液的可操作性,这无疑将极大地方便其整合到各种结构类型太阳能电池器件中。与传统硅基太阳能电池相比,量子点太阳能电池的制造成本可大幅度降低,重点介绍了几种...     

Sm掺杂ZnO QDs的制备及其荧光性能研究

通过研究不同碱/锌、钐/锌物质的量比制备了分散性良好的Sm掺杂氧化锌量子点（ZnO QDs）。通过紫外可见光谱（UV-vis）、X射线衍射（XRD）、场致发射透射电子显微镜（TEM）、能量色散X射线谱（EDS）、X射线光电子能谱（XPS）对样品做了表征。研究结果表明,n（Zn）∶n（OH^-）=1∶1、Sm掺杂量为4%（物质的量分数）时制备的ZnO QDs在383 nm紫外光激发下的荧光发射强度最强。并发现稀土钐离子的掺杂与ZnO QDs的氧空位（OV）形成有关。Sm掺杂后的ZnO QDs的氧空位浓度比未掺杂的高,且ZnO QDs氧空位的浓度越大,其荧光发射强度越强。     

二氧化钛包覆氧化锌纳米阵列光阳极的制备与性能

采用直流反应磁控溅射工艺,在ZnO纳米阵列的表面实现TiO2包覆,作为染料敏化太阳能电池光阳极,研究TiO2--ZnO核壳结构的形成机理和制备工艺对其光电性能的影响。利用X射线衍射仪、扫描电子显微镜、能谱分析仪表征光阳极材料的成分与结构。测试电池组件的伏安特性曲线、电压-时间曲线和电化学阻抗谱,分析TiO2包覆对电子传输性能和光电转换效率的影响机理。结果表明:磁控溅射制备的TiO2颗粒完整地包覆ZnO纳米阵列,使得纳米棒表面形貌由六棱柱向圆柱状转变,间隙变窄,直径较ZnO纳米阵列有所增加,阵列有序度得到改善。随着延长染料吸附时间和TiO2包覆,光阳极界面电子传输阻抗显著增加,光生电子的寿命也得到提高。经过包覆的光阳极能够作为阻挡层钝化表面缺陷,抑制复合的发生,从而提高开路电压和填充因子。经过包覆的光阳极其光电转换效率相对于纯ZnO纳米阵列提高了132%。     

CuO表面修饰ZnO量子点及其光学性能

采用均匀沉淀法,用Zn(Ac)2·2H2O为原料,KOH为沉淀剂,制备出ZnO量子点,再由Cu(Ac)2·H2O水解形成的CuO对ZnO表面进行修饰.用透射电镜、X射线衍射、紫外-可见光光度计、荧光等手段表征、分析了经过表面修饰的ZnO的形貌、粒度、衍射图谱、吸收光谱和荧光光谱,并考察了时间和反应物浓度等反应条件对ZnO表面修饰的影响.结果表明:所制备的ZnO平均粒径约为4nm,在水浴16h后CuO对ZnO的修饰效果趋于稳定,修饰后在ZnO颗粒包覆了CuO,阻止了ZnO颗粒的进一步长大,CuO表面修饰使ZnO可见发射强度大大降低.     

一种应用于钙钛矿太阳能电池的D-A-D型传输材料的合成及性能研究

提高钙钛矿太阳能电池的效率和稳定性是发展过程中的巨大挑战,通过引入添加剂、钝化剂、保护层等方法,在钙钛矿层和空穴传输层之间引入界面修饰层对界面传输进行改善,抑制电子和空穴复合,是提高钙钛矿太阳能电池效率和稳定性的有效手段。报道了一种具有较高载流子迁移率的顺式D-A-D（Donor-Acceptor-Donor）型三苯胺偶氮化合物（TPA）₂Ab,将其用作钙钛矿层和Spiro-OMeTAD层之间的传输层,记为电荷分离层。电荷分离层的引入有效增加了空穴传输,抑制载流子复合,钝化了钙钛矿层表面陷阱;并通过掺杂碘化氢进一步优化了钙钛矿层表面形貌,降低了传输阻值。同没有电荷分离层的参比电池对比,发现有电荷分离层修饰的钙钛矿太阳能电池效率由14.24%提升至16.14%,提升近14%。同时,电荷分离层的引入可以减弱水氧对钙钛矿层的破坏,因此电池稳定性也得到显著提高,电池的效率依然保持在85.69%。     

缓冲层在有机太阳能电池中的应用

有机太阳能电池的有机活化层与阴、阳极接触界面的性质对器件性能起着重要的作用。本文综述了近年来有机太阳能电池中使用的阴、阳极界面缓冲材料的类型和工作机制。结果表明,阴、阳极缓冲层的界面修饰对太阳能电池的能量转换效率、寿命和稳定性具有决定性的影响。因此,缓冲层的特性研究对器件结构的改进和性能优化具有一定的指导意义。该研究为其它缓冲层材料在有机太阳能电池中的成功应用提供了有益的实验思路。     

量子点敏化太阳能电池研究进展

量子点敏化太阳能电池(quantum dot-sensitized solar cells,QDSSCs)由于其理论转化效率高(44%)、带隙可调、价格低廉和稳定性好等优点引起了广泛关注。本文就QDSSCs的结构组成、工作原理、量子点(quantum dots,QDs)的合成方法、限制效率的因素以及优化方法等进行了综述,总结了量子点的两种合成方法即原位沉淀法和非原位沉淀法。与此同时,分析了目前影响QDSSCs效率的主要因素,如电子-空穴对的复合、光阳极结构不完善、电解质性能不佳等,最后对如何提高QDSSCs光电转化效率的研究重点和方向进行了展望,指出可通过改性量子点敏化剂、优化光阳极半导体及改善量子点与半导体间的界面特性等方法提高转换效率。     

Y系列梯形稠环非富勒烯受体研究进展

随着新型高性能非富勒烯受体(NFA)的出现,有机太阳能电池(OSC)进入了以高功率转换效率(PCE)为特征的研究新阶段。尤其是2019年Y系列非富勒烯受体的合成,通过对Y系列分子的缺电子核、侧链和端基的修饰,人们可以便捷地调控受体能级,优化分子形貌,从而得到性能更加优异的受体分子,基于Y系列的非富勒烯受体小分子的器件效率已经达到17%并有望突破20%。在此我们总结了Y系列受体分子的设计与器件应用中的研究进展,并展望Y系列非富勒烯电子受体未来发展。     

Optimization of inverted bulk heterojunction polymer solar cells

We have successively fabricated inverted bulk heterojunction polymer solar cells employing ZnO and MoO₃ as electron and hole selective layers, respectively. The device structure is ITO/ZnO/P3HT: PCBM/MoO₃/Al. Differently from conventional polymer solar cells, ITO and Al work as electron and hole collecting electrodes in this inverted structure, respectively. We have found the optimal thickness of ZnO and MoO₃ to be 100 nm and 5 nm, respectively. The highest PCE was obtained to be 3.32% under AM 1.5 illumination at 1,000W/m², which is the highest PCE of inverted solar cells reported previously in the literature.     

Core-shell structured photovoltaic devices based on PbS quantum dots and silicon nanopillar arrays

We fabricated three-dimensional silicon nanopillar array (SiNP)-based photovoltaic (PV) devices using PbS quantum dots (QDs) as the hole-transporting layers. The core-shell structured device, which is based on high aspect ratio SiNPs standing on roughed silicon substrates, displays a higher PV performance with a power conversion efficiency (PCE) of 6.53% compared with that of the planar device (2.11%). The enhanced PCE is ascribed to the increased light absorption and the improved charge carrier collections in SiNP-modified silicon surfaces. We also show that, for the core-shell structured device, the thickness of the shell layer plays a critical role in enhancing the PV performance and around five monolayers of QDs are preferred for efficient hole-transporting. Wafer-scale PV devices with a radial PbS/SiNP heterojunction can be fabricated by solution phase techniques at low temperatures, suggesting a facile route to fabricate unique three-dimensional nanostructured devices.     

Effect of electrodeposition and annealing of ZnO on optical and photovoltaic properties of the p-Cu2O/n-ZnO solar cells

Cu₂O/ZnO p–n heterojunction solar cells were fabricated by rf sputtering deposition of n-ZnO layer, followed by electrodeposition of p-Cu₂O layer. The different electrodeposition potentials were applied to deposit Cu₂O on ZnO. The particle size, crystal faces, crystallinity of Cu₂O is important factor which determine the p–n junction interface and consequently their effect on the performance of the heterojunction solar cell. It is observed that at −0.6 V, p-Cu₂O film generates fewer surface states in the interband region due to the termination of [1 1 0] resulting in higher efficiency (0.24%) with maximum particle size (53 nm). The bandgap of Cu₂O at this potential is found to be 2.17 eV. Furthermore, annealing of ZnO film was performed to get rid of deteriorating one and two dimensional defects, which always reduce the performance of solar cell significantly. We found that the solar cell performance efficiency is nearly doubled by increasing the annealing temperature of ZnO thin films due to increasing electrical conductance and electron mobility. Doping studies and fine tuning of the junction morphology will be necessary to further improve the performance of Cu₂O/ZnO heterojunction solar cells.     

The Influence of Physical Properties of ZnO Films on the Efficiency of Planar ZnO/Perovskite/P3HT Solar Cell

ZnO thin films prepared by pulsed laser deposition at low temperature are utilized as the electron transport layer in CH₃NH₃PbI_3?xCl_x‐based perovskite solar cells with a planar heterojunction structure. Oxygen pressure greatly influences the transparent and conductive properties of ZnO films, which are extremely important as electron transport layer for the perovskite solar cells. The transparent and conductive properties of the films under different oxygen pressures are studied by ultraviolet‐visible spectrophotometer and Hall effect measurement system. Through controlling the oxygen pressure, transparent ZnO films with high conductivity are grown and adopted as electron transport layer for planar perovskite solar cell with a power conversion efficiency of 6.3%. After further surface modification of ZnO electron transport layer with [6,6]‐phenyl‐C61‐butyric acid methyl ester, the efficiency of the planar solar cell increases to 7.5%.     

Effect of CdSe quantum dots on the performance of hybrid solar cells based on ZnO nanorod arrays

This paper reports the fabrication and interface modification of hybrid inverted solar cells based on ZnO nanorod arrays and poly (3-hexylthiophene). CdSe quantum dots (QDs) are grafted to the ZnO nanorod array successfully by bifunctional molecule mercaptopropionic acid to enhance the device performance. The power conversion efficiency of the device is increased by 109% from 0.11% to 0.23% under simulated 1 sun AM 1.5 solar illumination at 100 mW/cm² after the modification. The grafting of CdSe QDs effectively enhanced the excition generation and dissociation on the organic/inorganic interface. This work may provide a general method for increasing the efficiency of organic–inorganic hybrid solar cells by interface modification.     

High Efficiency Computer Simulation for Au/n-ZnO/p-Si/Al Schottky-Type Thin Film Heterojunctions

In this paper, the Au/n-ZnO/p-Si/Al heterojunction for developing solar cells with high conversion efficiency and low cost were studied. The Au/n-ZnO/p-Si/Al HIT (heterojunction with intrinsic thin-layer) solar cells were analyzed and designed by AFORS-HET software. The characteristics of such cells with emitter intrinsic layer thickness and interface states density are discussed. The simulation results show that the key role of the intrinsic layer inserted between the ZnO and crystalline silicon substrate p-Si is to decrease the interface states density. If the interface states density is lower than 10¹⁰ cm^?2.V^?1, a thinner intrinsic layer is better than a thicker one. The increase of the thickness of the emitter will decrease the short-current density and affect the conversion efficiency. The effect of Surface Recombination Velocity (SRV) front and back on the J-V characteristics of the Au/n-ZnO/p-Si/Al heterojunction solar cell has been studied with this simulation. With the optimized parameters set, the Au/n-ZnO/p-Si/Al solar cell reaches a high efficiency (η) up to 21.849 % (FF: 0.834, V_oc: 0.666 V, J_sc: 39.39 mA/cm²).     

Enhanced Thermal Stability of Inverted Polymer Solar Cells with Pentacene

In this study, we focused on the thermal stability of organic solar cells based on poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C₆₁-butyric acid methyl ester (PCBM), fabricated by blends of P3HT : PCBM : pentacene. Enhanced thermal stability of organic solar cells was achieved by introducing pentacene (Pc) into blends of P3HT : PCBM in organic solar cells with the structure indium tin oxide/ZnO/P3HT : PCBM : Pc/poly(3,4-ethylenedioxythiophene) : polystyrene sulfonate/Ag (ITO/ZnO/P3HT : PCBM : Pc/PEDOT : PSS/Ag). The donor-acceptor interfaces of devices with Pc were more stable than those without Pc in the active layer. During the thermal annealing process, the Pc in the P3HT : PCBM blends suppressed the crystallization of P3HT and PCBM, which was confirmed by optical microscopic images and UV-visible absorption spectra. The power conversion efficiency (PCE) of the device with Pc was reduced to no less than 70 % of its original efficiency after keeping it at 120 °C for 24 hours, while that of the non-Pc device was reduced to 13 % of its original efficiency after 24 hours at the same temperature. Based on these results, we propose a new Pc-blended organic solar cell that has advantages in the thermal annealing process.     

自组装制备硫化铜空穴传输层用于钙钛矿太阳能电池

采用自组装方法制备了硫化铜作为钙钛矿太阳能电池的空穴传输层。这种方法具有低成本且可大规模制备等优点。采用紫外-可见吸收光谱和紫外光电子能谱对硫化铜薄膜进行了光学性能和能带结构表征;采用原子力显微镜对硫化铜薄膜进行了表面形貌表征;采用Keithley 2410系统测试了器件的电流密度-电压特性。结果表明,硫化铜具有良好的光学透过性、适宜的能级和均匀致密的表面覆盖,采用硫化铜制备的器件具有14.97%的光电转换效率,同时具有可忽略不见的滞后现象。将器件置于空气中14 d后还能保持80%以上的原始效率,表明器件具有良好的稳定性。以上结果表明,采用自组装方法制备的硫化铜薄膜具有优良的性能,对未来钙钛矿太阳能电池的大规模制备及应用提供了一定的借鉴意义。     

Tri-metallic quantum dot under the influence of solvent additive for improved performance of polymer solar cells

CdTeSe colloidal quantum dot (QD) was used to enhance photon capture in thin film polymer solar cells (TFPSC). The QDs were synthesized in aqueous media from two different precursors. Bulk heterojunction (BHJ) polymer blends composed of P3HT and PCBM were used as an absorber layer of the solar cell to investigate the effect of QDs. Different concentrations of QDs were used in the polymer matrix, which significantly impacted the power conversion efficiency (PCE) of the doped devices. More device performance growth was recorded by employing a small amount of solvent additives to disperse the QDs and increase the polymer's crystallinity in the medium. Hence, the addition of 1, Chloronaphthalene (CN) solvent additive in the QD-doped bulk heterojunction film further enhanced the overall performance of the TFPSC due to improved film morphology that has significantly influenced the charge transport processes. Consequently, the PCE of the solar cell increased by nearly 50% compared to the pristine TFPSC due to the effect of solvent additives.     

Bottom-up self-assembly of macroporous ZnO nanostructures for photovoltaic applications

The present study utilized a template-assisted electrodeposition route for the bottom-up epitaxial growth of macroporous zinc oxide nanostructures. To this end, the ZnO seed layer was coated on the p-type silicon substrates using a radio frequency magnetron sputtering technique to form a p-n heterojunction. Then, polymer microspheres were implanted on ZnO/Si substrates to act as a template. Subsequently, ZnO nanostructures were electrodeposited through the interstitial spaces between the microspheres. After the deposition, the microspheres were removed by dissolving in chloroform solvent, forming a porous structure. The planar and cross-sectional electron microscopy analyses exhibited a uniform macroporous morphology with an average pore diameter of ∼1 μm. The pores were homogeneously distributed on the surface of the electrodeposited ZnO layer. The advantage of this technique over the top-down approaches, such as electrochemical etching, is that the porosity and size of pores can be easily adjusted by varying the concentration and diameter of microsphere templates. The optical investigations revealed enhancement in photon absorption and photoluminescence (PL) intensity due to multiple light scattering in the pore walls of the deposited ZnO nanostructures. For the templated sample, a PL blue shift was observed due to the reduction in crystallite size of ZnO nanostructures. A heterojunction thin film solar cell was designed by the metallization of ZnO/p-Si samples to study the power conversion capability of macroporous ZnO nanostructures. The photovoltaic performance of the developed devices was evaluated under a solar light simulator. The device based on the templated sample showed increased shunt resistance and reduced series resistance compared to the flat sample. The optoelectrical results indicated an efficiency improvement for the fabricated solar cells based on the macroporous ZnO sample due to its higher exposed area and increased rate of electron-hole generation.