Investigation of Organic Solar Cells Based onDonor——A ccepter Heterojunction

The single-l ayer structure and heterojunction structure organic solar cells based on copper phthalocyanine (CuPc),3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA) and fullerene C60 were fabricated to study their photovoltaic (PV) properties. The PV performance of heterojunction structure solar cells was improved compared with the single layer structure cell.This is due to the introduction of donor-acceptor heterojunction that both expands the absorption range and offers efficient excit on dissociation site.In heterojunction structure solar cells,the PV performance of device with C60 as acceptor has highly improved because C60 has longer diffusion length o f excitons.     

Investigation of Organic Solar Cells Based on Donor-Accepter Heterojunction

The single-layer structure and heterojunction structure organic solar cells based on copper phthalocyanine(CuPc),3,4,9,10-Perylenetetracarboxylic dianhydride(PTCDA)and fullerene C60 were fabricated to study their photovoltaic(PV)properties.The PV performance of heterojunction structure solar cells was improved compared with the single layer structure cell.This is due to the introduction of donor-acceptor heterojunction that both expands the absorption range and offers efficient exciton dissociation site.In heterojunction structure solar cells,the PV performance of device with C60 as acceptor has highly improved because C60 has longer diffusion length of excitons.     

Nanoscale Morphology Control in Functional Polymer Systems

1 Results In high-performance organic solar cells,the photoactive layer consists of a blend of an electron donor and an electron acceptor constituent,a so-called bulk heterojunction.The requirements to morphology of the efficient photoactive layer are nanoscale phase separation,which provides large interface area for exciton dissociation,and at the same time continuous pathways for transport of free charge carriers to the appropriate electrodes.In this context,the research is now focused on a better und...     

a—Si／c—Si异质结太阳能电池制造中的技术分析

应用数值模拟方法计算ｐ（ａ－Ｓｉ：Ｈ）／ｎ（ｃ－Ｓｉ）异质结和ｐ（ａ－Ｓｉ：Ｈ）／ｉ（ａ－Ｓｉ：Ｈ）／ｎ（ｃ－Ｓｉ）结－异质结太阳能电池的电场强度分布，指出异质结电池制造中对ａ－Ｓｉ：Ｈ膜厚的选择，进而对嵌入本征ｉ（ａ－Ｓｉ：Ｈ）层的结－异质结太阳能电池设计进行分析并讨论其稳定性     

双重优化对基于P3HT:PCBM有机太阳能电池效率的提高

有效提高太阳能电池对光的吸收效率是提高太阳能电池能量转换效率的重要因素.在以poly(3-hexylthiophene)(P3HT)为电子给体材料,[6,6]-phenyl C60-butyric acid methyl eater(PCBM)为电子受体材料的有机太阳能电池中,Poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)与活性层之间插入不同厚度的P3HT层,并在P3HT层最佳厚度的基础上,进一步在活性层中掺杂不同比例的Ag纳米粒子,双重优化了电池器件.当插入45 nm的P3HT层及掺杂质量比为5%的Ag纳米粒子时活性层薄膜的形貌及内部结构得到了改善,电池对光的吸收,及外量子效率得到了显著地提高,并出现红移现象.在25°C,光强为100 mW/cm2的条件下测量其短路电流密度JSC为11.21 mA/cm2,能量转化效率PCE为3.79%.     

材料带隙和阴极功函数对有机太阳能电池开路电压的分析

利用AMPS-1D软件研究了材料带隙和阴极功函数对异质结有机太阳电池的开路电压的影响。仿真实验结果表明:有机太阳电池的开路电压和材料带隙满足线性关系;活性层材料的带隙一定时,开路电压随阴极功函数的增大而减小,同时开路电压随温度的升高而减小,并呈现一次指数衰减的趋势;活性层内部载流子的复合率随阴极功函数的增大而增大,进而导致器件内部电场强度的减小。     

有机太阳能电池的研究进展

回顾了近五年有机太阳能电池在电池材料和器件性能方面的研究进展．在材料方面,合成具有低带隙的化合物,使之与太阳光谱有更好的匹配,以提高对太阳光的吸收范围;在器件方面,通过使用异质结和纳米结构,使之在增加光吸收的同时保证激子的分离与有效迁移．有机聚合物太阳能电池是有机太阳能电池的发展方向,设计并合成具有低带宽和低HOMO能级的D—A型聚合物是提高其理论光能转化效率的关键．通过改进与提高电池的制作技术,充分挖掘新材料的潜力,将获得较大光能转换效率的有机太阳能电池．     

Polaron-pair-dependent equivalent circuit parameters of organic solar cells based on CuPc and C<Subscript>60</Subscript>

We present the current-voltage characteristics of organic solar cells based on single and double heterojunction of copper phthalocyanine (CuPc) and C60 by introducing a constant JP instead of photo-current density Jph to represent the density of polaron-pairs generated from excitons at D/A interface. A diode Dext models polaron-pair dissociation, and a diode Drec stands for loss due to polaron-pair recombination. The photovoltaic response under AM 1.5 solar illumination at an intensity of 100 mW/cm2 is para...     

Nanoscale structural and electronic evolution for increased efficiency in polymer solar cells monitored by electric scanning probe microscopy

Control of blend morphology at multi-scale is critical for optimizing the power conversion efficiency （PCE） of plastic solar cells. To better understand the physics of photoactive layer in the organic photovoltaic devices, it is necessary to gain understanding of morphol- ogy and the corresponding electronic property. Herein we report the correlation between nanoscale structural, electric properties of bulk heterojunction （BHJ） solar cells and the annealing-induced PCE change. We demonstrate that the PCE of BHJ solar cells are dramatically improved （from 1.3 % to 4.6 %） by thermal annealing, which results from P3HT crystalline stacking and the PCBM aggregation for interpenetrated network. The similar trend for annealing- induced photovoltage and PCE evolution present as an initial increase followed by a decrease with the annealing time and temperature. The surface roughness increase slowly and then abruptly after the same inflection points observed for photovoltage and PCE. The phase images in electric force microscopy indicate the optimized P3HT and PCBM crystallization for interpenetrating network formation considering the spectroscopic results as well. From the correlation between surface photovoltage, blend morphology, and PCE, we propose a model to illustrate the film structure and its evolution under different annealing conditions. This work would benefit the better design and optimization of the morphology and local electric proper- ties of solar cell active layers for improved PCE.     

Efficient bulk heterojunction photovoltaic cells using small-molecular-weight organic thin films

The power conversion efficiency of small-molecular-weight and polymer organic photovoltaic cells has increased steadily over the past decade. This progress is chiefly attributable to the introduction of the donor-acceptor heterojunction that functions as a dissociation site for the strongly bound photogenerated excitons. Further progress was realized in polymer devices through use of blends of the donor and acceptor materials: phase separation during spin-coating leads to a bulk heterojunction that removes the exciton diffusion bottleneck by creating an interpenetrating network of the donor and acceptor materials. The realization of bulk heterojunctions using mixtures of vacuum-deposited small-molecular-weight materials has, on the other hand, posed elusive: phase separation induced by elevating the substrate temperature inevitably leads to a significant roughening of the film surface and to short-circuited devices. Here, we demonstrate that the use of a metal cap to confine the organic materials during annealing prevents the formation of a rough surface morphology while allowing for the formation of an interpenetrating donor-acceptor network. This method results in a power conversion efficiency 50 per cent higher than the best values reported for comparable bilayer devices, suggesting that this strained annealing process could allow for the formation of low-cost and high-efficiency thin film organic solar cells based on vacuum-deposited small-molecular-weight organic materials.     

硅MINP太阳电池的多子隧道效应

本文对MINP电池中的多子隧道电流进行了计算分析,从其伏安特性曲线得出太阳电池所允许的氧化层厚度的极限。     

单层有机发光二极管中电场与载流子密度的分布

建立了单层 (有机发光二极管 )中载流子注入、输运和复合的理论模型 ,通过求解非线性Painleve方程得到了电场强度随坐标变化的解析函数关系式 ,计算并讨论了载流子迁移率对电场强度、载流子密度等的影响。结果表明 :空间电荷分布不均匀造成了电场强度的不均匀分布。当在器件中占主导地位的载流子具有较低的迁移率或少数载流子具有较高的迁移率时 ,有利于载流子的输运与复合 ,发光性能可得到较大提高。     

一种咔唑-苯并噻二唑共聚物的合成与光伏性能研究

以N-十二烷基-2,7-咔唑为给体单元、5,6-二辛氧基二噻吩苯并噻二唑为受体单元，通过Suzuki偶联反应合成了一种具有给-受体结构的共轭聚合物聚N-十二烷基-2,7-咔唑-5,6-二辛氧基-4,7-二噻吩-2-基-苯并噻二唑（PC-DODTBT），并研究了该聚合物的光物理与电化学性能。结果表明，以PC-DODTBT为电子给体，PCBM为电子受体，制得的共混体相异质结太阳能电池在AM1.5、100 mW/cm²模拟太阳光下，开路电压为0.88 V，短路电流为2.04 mA/cm²，填充因子为0.51，能量转换效率为0.92%。     

二硫化钼-硅异质结太阳电池的原位制备及器件模拟

 二维材料与晶体硅形成的异质结太阳电池是当前太阳电池研究热点之一,大多数研究都集中在石墨烯和硅形成的肖特基结太阳电池。为改善器件的能带结构,本研究采用具有一定禁带宽度的n-MoS₂二维半导体材料与p-Si 形成异质结太阳电池。通过实验研究了退火时间对MoS₂材料合成的影响,并对MoS₂-Si异质结的暗电流和光电流曲线进行测量和分析。通过异质结模拟软件wx-AMPS对MoS₂-Si异质结结构进行效率计算和能带分析,探讨了薄膜厚度和载流子浓度对器件开路电压的影响。     

Hybrid solar cells based on poly（3-hexylthiophene） and electrospun TiO2 nanofibers modified with CdS nanoparticles

Organic–inorganic hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nano bers were fabricated by solution process.The ef ciency of the device was improved by modifying CdS nanoparticles on the surface of TiO2 by electrochemical method.The CdS layer can lead to the increase of both open circuit voltage and short circuit current of the device,which are attributed to enhanced exciton dissociation and light absorption and suppressed carrier recombination by CdS at the heterojunction.However,too thick CdS layer led to increased series resistance and decreased ef ciency of the device.Therefore,the optimum condition of the CdS deposition was obtained,which increased the power conversion ef ciency of the device for about 50%.Our results indicate that the surface modi cation on the inorganic semiconductor layer is an effect way to improve the performance of the hybrid solar cells.     

ZnO/Cs2CO3双电子传输层有机太阳能电池

有机太阳能电池的异质结界面是影响其性能的一个重要因素.以氧化锌/碳酸铯作为双电子传输层,改善电子传输层与活性层的界面接触并提高电子传输能力.利用溶胶-凝胶法制备OSCs器件,通过优化的双电子传输层,使基于PTB7-Th:PC₇₁BM的OSCs器件的最高效率达到了8.08%,其相较于ZnO电子传输层器件提高了10.68%.实验表明,由于ZnO/Cs₂CO₃ ETLs具有最佳的表面形貌和光吸收,其填充因子、短路电流密度和电子迁移率都显著提升.这种ZnO/Cs₂CO₃双电子传输层为OSCs性能改善提供了新的思路.     

基于ZnO缓冲层的有机太阳能电池数值分析

氧化锌(ZnO)材料具有良好导电性、光透性和稳定性,在光电器件中具有重要用途.利用AMPS-1D探究ZnO作为缓冲层对有机太阳能电池性能的影响.研究发现:添加ZnO缓冲层的有机太阳能电池开路电压、光电转化效率等性能有显著的提高; 电子-空穴产生率和空穴电流密度随着ZnO薄膜厚度增加而减小,而电荷态密度和电子电流密度随着ZnO薄膜厚度增加而增大.     

Recent development of organic electron transport materials

This article reviews the recent development of organic electron transport materials applied in the fields of organic photoconductors, light-emitting diodes, field-effect transistors and solar cells. Several technologies for charge carrier mobility measurement are summarized and compared, and a series of basic principles for designing high-performance organic electron transport materials are suggested as well.     

原子层沉积增强微纳结构硅电池的光电性能

本文用原子层沉积技术在硅表面沉积氧化铝作为钝化层、掺铝氧化锌薄膜作为透明电极，应用于有金字塔结构和黑硅结构的光伏电池上。通过反射光谱、电流-电压曲线、外量子效率等测试，比较平面硅、金字塔绒面硅和黑硅三种不同结构电池的光电性能。通过在金字塔结构表面沉积10个循环氧化铝作为钝化层，180 nm掺铝氧化锌作为透明电极，光电转换效率达到11.23%，短路电流28.72 mA/cm2，开路电压0.548 V，填充因子0.71。相比于没有钝化层和掺铝氧化锌薄膜的样品，电池各方面性能都得到提高。将该钝化层和透明电极应用于黑硅电池上获得了8.89%的光电转换效率。证明掺铝氧化锌作为透明电极、氧化铝作为钝化层，对微纳结构电池性能有明显提高。     

a－Si∶H Schottky势垒太阳能电池结构中载流子俘获对电场的调制效应

本文应用计算机数值模拟方法研究了ａ－Ｓｉ：ＨＳｃｈｏｔｔｋｙ势主太阳能电池结构中载流子俘获对电场的调制效应．结果表明，无论先生空穴或电子俘获都将改变电池中的电场分布，导致准中性区（低场“死层”）出现或扩大，从而减小了电池的载流子收集长度，这是引起ａ－Ｓｉ：ＨＳｃｈｏｔｔｋｙ势垒太阳能电池光致性能衰退的一个重要原因．