Workshop on recent development of perovskite solar cells

The purpose of the workshop is to invite researchers working on the field of perovskite solar cells to discuss current status, to identify significant problems, to present latest research, and to seek for potential  collaborations. The workshop includes invited talks and open discussions. The workshop will be held on Aug 10th (Thu.) in Beijing Computational Science Research Center (CSRC). This workshop is supported by National Key Research and Development Program of China Grant No. 2016YFB0700700.

All interested are welcome.

Registration:  http://cn.mikecrm.com/RxCOrr7       (Deadline：Aug.6th)

For further information please see:

http://www.csrc.ac.cn/en/collaboration/visitor-guide/

1.戴松元，男，国家973首席科学家，教授/博生博导，政府特殊津贴获得者，华北电力大学可再生能源学院院长，新型薄膜太阳电池北京市重点实验室主任。先后主持和完成多项国家重点基础研究（973）、863、省部级目和中科院创新方向性项目，以及国际合作项目。目前正主持国家重点专项“钙钛矿电池关键材料设计制备及高性能柔性器件”、国家自然基金面上项目和北京市科委重大项目，教育部“111”引智项目和科技部重点领域创新团队“新型薄膜太阳电池基础及应用研究”。自1994年以来，先后从事染料敏化太阳电池材料、机理和器件，以及产业化示范研究。先后多次在国际会议上就取得的成果做特邀报告，在本领域权威国际期刊上共发表SCI论文300多篇，获得发明专利授权40余项，出版专著3部，基于在新型太阳电池研究方面的突破性进展，2013年被中国可再生能源学会光伏专委会授予第13届“中国光伏成就奖”。

2. Prof. Bin Hu worked in University of Tennessee, Knoxville, TN 37996, USA and also at Beijing Jiaotong University, China. He got his PhD degree from Chinese Academy of Sciences in 1991, and in 2002, he joined the University of Tennessee, Knoxville as Assist Professor, he was promoted to full Professor in 2012. His research interest include Organic spintronics, organic thermoelectrics, organic solar cells. He has got many awards including NSF Career Award and  Chancellor's Research and Creative Achievement Professional Promise Award of University of Tennessee, Knoxville.

3.刘生忠，1983年获陕西师范大学理学学士学位，1986年获兰州大学理学硕士学位，1992年获美国西北大学(Northwestern University)工学博士学位。先后在美国Argonne National Laboratory（阿贡国家实验室）、BP Solar (Solarex)、United Solar等高科技公司从事研究工作约20年，于2011年底全职回国工作，现任陕西师范大学教授和中国科学院大连化学物理研究所研究员。研究领域主要包括太阳能光伏材料、纳米材料、薄膜材料、TCO薄膜的电化学沉积、激光表面处理和光伏技术的开发、放大和生产。

  在基础研究方面，刘博士已经取得了显著成果，曾在国际顶级期刊上发表了多篇论文，包括Science、Nature、Science Advances、Nature Communications、Advanced Materials、Angew. Chem. Int. Ed.、Energy & Environmental Science等。

  回国后，刘博士已经在中国科学院大连化学物理研究所组建了研究组，在陕西师范大学组建了陕西省能源新材料与器件重点实验室、陕西省能源新技术工程实验室、陕西师范大学新能源材料研究所、创新团队和新型交叉学科团队等。回国后已发表SCI论文80多篇，其中，3篇论文进入ESI高引论文（top 1%），其中一篇进入ESI“HOT Article”, (top 千分之一)。

  刘博士的应用成果也得到广泛关注。与三家企业有密切合作，总投资达1000万。

4.汪林望简历：Wang Bio_2017.pdf

5.唐江，华中科技大学武汉光电国家实验室（筹）教授，基金委优秀青年基金获得者。2003年本科毕业于中国科学技术大学，2006年硕士毕业于中国科学院长春应用化学研究所；2010年博士毕业于多伦多大学。随后进入美国IBM沃森研发总部从事博士后研究工作，2012年加入华中科技大学。唐江教授一直从事新型太阳能电池研究，以第一或者通讯作者身份在Nature Photonics, Nature Materials, Nature Energy, Nature Communications等期刊发表学术论文80余篇，被引用4000余次。目前研究方向为硒化锑薄膜太阳能电池，非铅钙钛矿单晶材料与探测器件。

6.周欢萍研究员目前任教于北京大学工学院材料科学与工程系，她于2010年在北京大学化学与分子工程学院获得博士学位，2010-2015年在美国加州大学洛杉矶分校从事博士后研究工作。研究兴趣主要集中于具有光电特性的无机以及无机/有机杂化材料的多维度控制，包括纳米尺度(可控合成及生长机理、自组装)，微米尺度(薄膜生长，缺陷钝化，界面调控)以及宏观尺度(器件构筑)，并探索其在能源领域，特别是太阳能电池的应用基础研究。相关研究成果以通讯/第一作者在Science, Nat. Commun., J. Am. Chem. Soc., Nano Lett., Adv. Mater., ACS Nano, Energy Environ. Sci., Adv. Energy Mater., Adv. Funct. Mater.等。他引次数>8000次。单篇最高他引>2000次；H-index为32。共发表近70余篇SCI论文，其中IF>10的为36篇。ESI高引用论文18篇。授权多项美国及国际专利。曾获北京大学优秀博士论文奖、美国加州大学洛杉矶分校博士后校长奖。

7. 张立军，男，吉林大学材料科学与工程学院，教授&博士生导师。2003年本科毕业于东北师范大学，2008年在吉林大学获理学博士学位，2008－2014年先后到美国橡树岭国家实验室、美国国家可再生能源实验室、美国科罗拉多大学波尔得分校任博士后研究员、研究助理教授。长期基于大规模材料计算机模拟，从事半导体功能材料的能带调控和新材料设计研究。共发表SCI论文~65篇，第一／通讯作者论文（38篇）包括Nature Commun. (1)、Nature Reviews Materials (1)、Phys. Rev. Lett. (2)、J. Am. Chem. Soc. (3)、Nano Lett. (4)、ACS Nano (1)、Chem. Mater. (4)、Phys. Rev. B (14)。论文共被SCI引用1800余次，H因子值为20。担任《Scientific Reports》、《Journal of Semiconductors》期刊编委。

8.陈福荣国立清华大学讲座教授，专长电子显微学和电子光学设计及电致变色。在台湾得到诸多国家等级奖项：例如，科技部杰出研究奖，纳米科技杰出学术奖，杰出新创公司奖等。曾任台湾工研院顾问，MRS, IUCr等国际会议组织委员。在学术的发展，最主要是在电子显微学中建立一个全新的理论架构。定量得到材料在三维空间里的原子结构及外观形状能够准确到一个原子尺度。创立两个公司：智能节能玻璃和电子显微镜制造设计公司。文章发表计有在 NATURE, Nature Communication, PNAS, Nano Lett., Nano. Energy, ACS nano, Langmuir, J. Am.  Chem. Soc. etc.

9.范斌，现任协鑫集团副总工程师，苏州协鑫纳米科技有限公司总经理。2004年在清华大学获学士学位，2006年在清华大学获理学硕士学位，2010年于瑞士洛桑高等理工大学（EPFL）获理学博士学位。致力于钙钛矿太阳能电池的产业化开发，带领团队建成全球第一条大面积（45x65cm）钙钛矿光伏组件中试生产线。 

Homepage: https://www.csrc.ac.cn/en/event/workshop/2017-07-29/74.html

 Homepage: https://www.csrc.ac.cn/en/event/workshop/2017-07-29/74.html

1.Preparation and Optimization of Materials for Efficient Perovskite Solar Cells

Songyuan Dai^{1, 2}, Xu Pan², Zhan'ao Tan¹, Jun Zhu², Jianxi Yao¹

¹ Beijing Key Laboratory of Novel Thin Film Solar Cells,Renewable Energy School, North China Electric Power University, Beijing, 102206, P. R. China. Email: sydai@ncepu.edu.cn

² Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Chinese Academy of Sciences, Hefei, 230031, P. R. China.

A novel mesoporous ETL based on La doped BaSnO₃ (LBSO) is investigated here. The LBSO nanoparticles are synthesized under relatively mild conditions and proved to be a suitable material for mesoporous ETL. After optimization, solar cells using mesoporous LBSO show the best power conversion efficiency of 15.1%. A TiO₂/ZnO/C₆₀ trilayer fabricated on a transparent fluorine-doped tin oxide (FTO) glass substrate was used as a compound ETL in planar heterojunction PSCs. With the aid of ZnO within the compound ETL, both of annealling temperature and duration of CH₃NH₃PbI_3-xCl_x were reduced. The best-performing PSC based on the TiO₂/ZnO/C₆₀ electron transport trilayer achieve a PCE of 18.63% with an FF of 79.12%.

A uniform, pinhole-free and incomplete pore filling in porous TiO₂ film of PbI₂-free perovskite layer was prepared by the sandwich structure MAI-PbI₂-MAI precursor film. Compare to the conventional two-step method, the devices fabricated from the sandwich structure MAI-PbI₂-MAI precursor films shown a dramatic improvement for all the performance parameters, and a promising efficiency of 17.8% was achieved.

A new class of hole-transporting materials (HTM) containing tetraphenylmethane (TPM) core have been developed. After thermal, charge carrier mobility, and contact angle tests, it was found that TPA-TPM (TPA: arylamine derivates side group) showed higher glass-transition temperature and larger water-contact angle than spiro-OMeTAD with comparable hole mobility.By adopting low pressure vapor assisted process (LP-VASP), we systematic studied the effect of the type of A cation, the type of X halide, and the structure on the photovoltaic properties. In LP-VASP, the evolution of crystal structure and mechanism of carriers transport showed many different results compared with that of the PSC prepared by solvent approaches. We achieved PCE of 17.40% in planar PSCs with mixed halide sources. There are some studies going on based on LP-VASP, such as the introduction the pseudohalogen into the structure of ABX₃.

References

1. X. Zhang, J. Ye, L. Zhu, H. Zheng, X. Liu, X. Pan and S. Dai, ACS Appl. Mater. Interfaces, 2016, 8, 35440-35446.

2. L. Zhu, Z. Shao, J. Ye, X. Zhang, X. Pan and S. Dai, Chem. Commun., 2016, 52, 970.

3. L. Zhu, J. Ye, X. Zhang, H. Zheng, G. Liu, X. Pan and S. Dai, J. Mater. Chem. A, 2017.

4. T. Du, N. Wang, H. Chen, H. Lin, H. He, ACS Appl. Mater. Interfaces 2015, 7 (5), 3382-3388.

 2.Investigating Polarization and Spin Effects on Photovoltaic Actions in Organic-Inorganic Perovskite Solar Cells 

Bin Hu

Beijing Jiaotong University, Beijing 100044, China

Department of Materials Science and Engineering

University of Tennessee, Knoxville, TN 37996, USA

Abstract: Organic-inorganic perovskites are unique electrically polarizable semiconducting multifunctional materials with non-degenerate spin states. Therefore, organic-inorganic hybrid perovskites have become emerging photovoltaic materials with remarkable efficiencies. This presentation will present our recent studies on (i) the effects of electrical polarization on internal charge dissociation and transport and (ii) the effects of spin states on Jsc, Voc, and FF in perovskite solar cells by using magneto-optical measurement and circularly polarized photocurrent detection. Our studies indicate that the bulk polarization can largely interact with surface polarization, leading to interface-controllable bulk photovoltaic processes. This provides a convenient method for using interface engineering to control bulk dissociation and recombination during the development of photovoltaic actions. On the other hand, our recent studies found that replacing Pb with Sn can appreciably decrease the spin states (triplets) available for photovoltaic actions, causing a serious photovoltaic loss in lead-free perovskite solar cells. Furthermore, we found that doping can change the spin populations on singlet and triplet spin states, consequently increasing the spin states available for photovoltaic actions in lead-free Sn-based perovskite solar cells. This presents a new mechanism to tune the spin-orbital coupling towards enhancing photovoltaic efficiencies in lead-free Sn-based perovskite solar cells. This presentation will summarize the recent studies on polarization and spin effects in perovskite solar cells.

3. 钙钛矿 – 神奇的光伏光电材料

杨栋¹, 刘渝城¹，杨周¹, 刘生忠^1,2*

¹ 陕西师范大学应用表面与胶体化学教育部重点实验室；新能源材料研究所；材料科学与工程学院，西安

^2. 中国科学院大连化学物理研究所，大连洁净能源国家实验室，大连

* szliu@dicp.ac.cn

一种新型的有机和无机杂化的钙钛矿材料，由于其优异的光学吸收，极长的载流子扩散长度和极低的缺陷态密度，已经成为光电光伏领域的一个奇迹。在过去的几年中，它已经被广泛应用于各种光伏和光电应用中。在短短几年中，钙钛矿太阳能电池转换效率（PCE）已经从3.8%提高到22%。由于使用低温加工工艺，因此可以选用很多高分子基底，因此基于平面结构的太阳能电池，特别是柔性钙钛矿太阳能电池备受各界关注。比较溶液沉积法和真空沉积法，我们发展了真空交替沉积法（PbCl₂和CH₃NH₃I），已经被广泛采用制备具有良好均匀性和表面覆盖率的钙钛矿薄膜及其太阳能电池。

真空交替沉积法采用PbCl₂和CH₃NH₃I层与层交替沉积，目前已经发展成制备电池高稳定性、高效率的钙钛矿电池工艺。新的沉积过程保证了膜的均匀性、良好的表面覆盖率、平滑度和结晶相纯度，同时又不需要对沉积监测和控制措施的苛刻要求。在刚性玻璃衬底上，平面结构的钙钛矿电池转换效率高达19.6%，这是目前的最高效率。最高的柔性钙钛矿太阳能电池效率达16.09% - 柔性钙钛矿电池的最高效率。更重要的是，该器件长时间暴露在室温环境下，衰减很小，稳定性很高。选择一个代表性的电池暴露在实验室环境条件下1500小时后，其最终的电池效率高达初始效率的91%以上，电池效率衰减仅9%。

发展了快速升温反应析晶法制备了大尺寸钙钛矿单晶，高温稳定性、水蒸气稳定性、吸收光谱、缺陷态密度及光电性能等都远优于钙钛矿微晶薄膜样品。

参考文献：

[1]  D. Yang, R. Yang, X. Ren, X. Zhu, Z. Yang, C. Li, S. Liu*, Advanced Materials, http://dx.doi.org/10.1002/adma.201600446.

[2]  D. Yang, R. Yang, J. Zhang, Z. Yang, S. Liu, C. Li, Energy Environ. Sci. 2015, 8, 3208.

[3]  D. Yang, Z. Yang, W. Qin, Y. Zhang, S. Liu, C. Li, J. Mater. Chem. A 2015, 3, 9401.

4.Carrier localization due to dynamic disorder in the hybrid perovskite materials

Abstract: I will discuss our recent work for hybrid perovskite: (MA)PbI3, in particular the carrier localization and dynamics due to dynamic disorder. The random rotation of the MA (CH3NH3) molecule provides an interesting case for the dynamic disorder of the system. Due to the dipole moment of the MA molecule, the onsite potential will fluctuate in sub-picosecond time scale. Such disorder will induce wave function localization as described by the Anderson localization picture. The dynamic nature of the fluctuation will also drive carrier wave function to move in a random fashion, hence induce its mobility. I will discuss the comparison of the calculated mobility with the experiments. I will also discuss some recent works in 2D perovskite materials.

5.全无机非铅钙钛矿单晶制备及其光电器件研究 

  唐江  华中科技大学武汉光电国家实验室   

摘要: 以CH3NH3PbI3为代表的杂化钙钛矿材料具有优异的光电特性并已经实现高效的太阳能电池和发光器件，但铅的毒性会对其应用带来一定的限制。开发基于钙钛矿结构的非铅卤化物并探索其潜在的光电应用具有较高的研究价值。本报告将重点介绍本课题组在非铅钙钛矿特别是全无机双钙钛矿单晶材料制备、物理特性和器件应用方面的研究进展，主要包括Cs2AgBiBr6单晶的制备和在X射线探测方面的应用；Cs2AgInCl6单晶的制备及其在白光荧光粉方面的应用。报告也将简单介绍铋基钙钛矿量子点和Cs4CuSb2Cl12材料的研究进展。 

6.多维度钙钛矿晶体的可控制备及性能研究

周欢萍

 摘要：随着对有机／无机钙钛矿材料认识的加深，其更进一步的研究挑战主要是如何理性地设计晶体结构（热力学），调控其晶体生长过程（动力学），以实现所需要的晶体性质，从而更好地提高相应光电器件的性能及稳定性。我们围绕这一挑战开展了部分工作：1）从前驱体化学出发，系统研究了添加剂配位能力对晶体生长的调控，从一个新视角提出对晶体形貌、结构及微结构控制的控制变量，为提高器件光电转化效率提供了更加丰富的控制手段，并制备得到光电转换效率超过19%的太阳能电池；2）在配位的基础上，通过调控钙钛矿前驱体的酸碱环境，有效地降低了所形成的钙钛矿晶体中的缺陷态密度，提高了载流子寿命，由此进一步发展了晶体生长过程中的缺陷化学，从而服务于制备高质量的晶体以及构筑厚异质结的太阳能电池，并制备得到光电转换效率超过20%的太阳能电池；3）利用多种表征手段和测试方法对不同维度的钙钛矿晶体的成核、生长过程、微结构和表界面等进行了系统表征，提出了可能的反应机理，揭示了它们的光电性能与晶体形貌、晶体取向、结构、微结构、缺陷态之间的内在关联，并探索了材料的其它潜在应用价值。

7.Lead-free Halide Perovskites via Functionality-directed Materials Screening

张立军*

吉林大学  吉林省长春市前进大街2699号 130012

*E- mail: lijun_zhang@jlu.edu.cn  

    Hybrid organic-inorganic halide perovskites with the prototype material of CH₃NH₃PbI₃ have recently attracted much interest as low-cost and high-performance photovoltaic absorbers but one would like to improve its stability and get rid of toxic Pb. We used photovoltaic-functionality-directed materials screening approach to rationally design via first-principles DFT calculations Pb-free halide perovskites. Screening criteria involve thermodynamic and crystallographic stability, as well as solar band gaps, light carrier effective masses, reasonable exciton binding, etc. We considered both single atomic substitutions in AMX₃ normal perovskites (altering A, M and X individually)[1] as well as double substitution of 2M into B+C pair in A₂BCX₆ double-perovskites [2,3]. Chemical trends in phase stabilities and optoelectronic properties are discussed with some promising cases comparable to CH₃NH₃PbI₃. Meanwhile, our joint theory-experiment study indicates that highly-oriented Sn-based two-dimensional perovskites are promising Pb-free solar absorbers, showing power conversion efficiencies up to 5.94% (without the requirement of further device structure engineering) and more importantly high device stability.[4]  

参考文献：

1. Dongwen Yang, Jian  Lv, Xingang Zhao, Qiaoling Xu, Yuhao Fu, Yiqiang Zhan, Alex Zunger*,  and Lijun Zhang*, Chem. Mater. 29, 524 (2017).

2. Xin-Gang Zhao, Jihui  Yang, Yuhao Fu, Dongwen Yang, Qiaoling Xu, Liping Yu, Su-Huai Wei*,  and Lijun Zhang*, J. Am. Chem. Soc. 139, 2630 (2017).

3. Xin-Gang Zhao, Dongwen  Yang, Yuanhui Sun, Tianshu Li, Lijun Zhang*, Liping Yu, and Alex  Zunger, J. Am. Chem. Soc. 139, 6718 (2017).

4. Yuqin Liao，Hefei  Liu，Wenjia  Zhou，Dongwen  Yang, Yuequn Shang，Zhifang Shi，Binghan Li, Xianyuan Jiang, Lijun  Zhang*, Li Na Quan, Rafael Quintero-Bermudez, Brandon R. Sutherland,  Qixi Mi, Edward H. Sargent, and Zhijun Ning*, J. Am. Chem. Soc.  139, 6693 (2017).

 8.Solid-state reaction process (SSRP) for high quality of perovskite solar cell and CMOS imaging sensor

Fu-Rong Chen, Dept. of Engineering and System Science, National Tsing Hua University, Hsin Chu, Taiwan

Recently, hybrid perovskite material, ABX₃ (A= Cs, CH₃NH₃, NH₂CHNH₂; B= Pb, Sn; X = Cl, Br, I), has been received a great deal of attention as an active layer in the field of new generation solar cells. This materials is usually fabricated with a two-step solution process. However, the surface morphology, nucleation rate and grain growth rate of CH₃NH₃PbI₃ perovskite light-absorber prepared by solution process are hard to control. Here we first describe a solid-solid reaction process (SSRP) to fabricate an ultra-flat CH₃NH₃PbI₃ perovskite  thin film of  large grain size by directly contacting lead iodide thin film (PbI₂)  with methylammonium iodide powder (CH₃NH₃I) without any chemical reagents at 120℃ under regular atmospheric environment..  The SSRP reaction mechanism is investigated with by in-situ heating SEM. The atomic structure of the perovskite film is analyzed with low dose in-line holography. The innovative SSRP bring an easy approach to fabrication of planar heterojunction perovskite solar cells and allows us to achieve a power conversion efficiency of approximately 18%. Furthermore,  One of the methods to increase the sensitivity of the CMOS image sensors (CIS) is to enhance the pixel fill factor, which is the fraction of the photoactive area compared with the overall pixel size ratio. To address this issue, arrays of the microlenses on top of pixels or backside illumination CIS technology have recently been the mainstreams of the CIS market. However, those techniques are expensive and complex in the fabrication process. And, due to the limitation of light-receiving area, those approaches are facing a challenge to produce extremely high resolutions CIS (pixel size about 1μm) without any loss of sensitivity. Here, we first propose a hybrid CIS with a thin organic-inorganic perovskite (PVSK) photoelectric conversion layer as a photoactive materials of the CIS sensors to enhance pixel fill factor, without increasing fabrication cost and process complexity. An device of perovskie imaging sensor is fabricated and will be demonstrated.

9.钙钛矿技术商业化面临的挑战

摘要：钙钛矿太阳能电池的实验室效率已经超过多晶硅太阳能电池，接近于CIGS和CdTe。随着稳定性问题的逐渐解决，钙钛矿技术已经来到了产业化的关口。协鑫纳米的技术团队自2013年以来，一直致力于实现钙钛矿技术的商业化应用，建成了全球第一条大面积钙钛矿组件试验生产线。此报告将与大家分享我们的经验、教训，以及对未来的展望。 

Homepage: https://www.csrc.ac.cn/en/event/workshop/2017-07-29/74.html