钙钛矿薄膜气相制备的晶粒尺寸优化及高效光伏转换
|
摘要
钙钛矿薄膜的气相制备是一种极具潜力的工业化生产工艺,但薄膜的质量控制目前远落后于溶液制备法.本文通过建立PbI_2薄膜向钙钛矿薄膜完全转化过程中反应时间、晶粒尺寸与温度的关系,实现了薄膜的质量优化及大面积钙钛矿薄膜的制备,将薄膜的平均晶粒粒径从0.42μm优化到0.81μm.基于空间电荷限制电流模型对缺陷密度的研究显示,钙钛矿薄膜的缺陷密度由5.90×10~(16)cm~(–3)降低到2.66×10~(16)cm~(–3).光伏器件(FTO/TiO_2/C_(60)/MAPbI_3/spiro-OMeTAD/Au结构)测试显示,面积为0.045cm~2器件的平均光电转换效率从14.00%提升到17.42%,最佳光电转换效率达到17.80%,迟滞因子减小至4.04%.同时,基于180℃制备的1cm~2器件的光电转换效率达到13.17%.
Organometal halide perovskite is one of the most promising materials for high efficient thin-film solar cell.Solution fabrication process shows that the recorded power conversion efficiency(PCE) is 23.7%, however, large scale fabrication suffers the inevitable toxic solvent, preventing it from implementing the green commercialization. As one of the matured large-scale fabrication techniques, the vapor deposition is recently found to promise the green fabrication of perovskite thin film without toxic solvent. However, the PCE based on vapor deposition is considerably lower than that based on solution fabrication because of ineffective regulation methods of the perovskite films. So, there is intensive requirement for optimizing the growth of perovskite in vapor deposition for improving PCE, especially, developing a kind of quality regulation method of the perovskite films.In this study, we provide a method of adjusting grain size in vapor deposition method. The grain size optimization of MAPbI_3 films is realized by simply modulating the reaction temperature between PbI_2 films and MAI vapor. We set the reaction temperature to be 140 ℃, 160 ℃, 180 ℃ and 200 ℃ separately and establish the relationship between reaction time and grain size during the complete conversion of PbI_2 film into MAPbI_3 film. We find that the average grain size of the film increases first with growth temperature increasing from 140 ℃ to 180 ℃ and then decrease at 200 ℃, giving an average grain size of 0.81 μm and a largest grain size of about 2 μm at 180 ℃. The defect density of perovskite film is deduced from the space charge limited current model,showing that it decreases from 5.90×10~(16) cm~(–3) at 140 ℃ to 2.66×10~(16) cm~(–3) at 180 ℃. Photovoltaic devices with structure FTO/TiO_2/C_(60)/MAPbI_3/spiro-OMeTAD/Au are fabricated to demonstrate the performance. It is found that the devices with an active area of 0.045 cm~2 show that with the increase of grain size, the average PCE increases from 14.00% to 17.42%, and the best device shows that its PCE is 17.80% with 4.04% hysteresis index. To show the possibility of scaling up, we fabricate a uniform perovskite thin film with an area of about 72 cm~2, and a device with an active area of 1 cm~2, which gives a PCE of 13.17% in reverse scan. In summary,our research provides a method of regulating the grain size for the vapor deposition, which can improve device performance by reducing the trap density in perovskite film for suppressing the carrier recombination in grain boundary. Meanwhile, we prepare high performance devices and large area thin films, showing their potential in large area device fabrication and applications.
Organometal halide perovskite is one of the most promising materials for high efficient thin-film solar cell.Solution fabrication process shows that the recorded power conversion efficiency(PCE) is 23.7%, however, large scale fabrication suffers the inevitable toxic solvent, preventing it from implementing the green commercialization. As one of the matured large-scale fabrication techniques, the vapor deposition is recently found to promise the green fabrication of perovskite thin film without toxic solvent. However, the PCE based on vapor deposition is considerably lower than that based on solution fabrication because of ineffective regulation methods of the perovskite films. So, there is intensive requirement for optimizing the growth of perovskite in vapor deposition for improving PCE, especially, developing a kind of quality regulation method of the perovskite films.In this study, we provide a method of adjusting grain size in vapor deposition method. The grain size optimization of MAPbI_3 films is realized by simply modulating the reaction temperature between PbI_2 films and MAI vapor. We set the reaction temperature to be 140 ℃, 160 ℃, 180 ℃ and 200 ℃ separately and establish the relationship between reaction time and grain size during the complete conversion of PbI_2 film into MAPbI_3 film. We find that the average grain size of the film increases first with growth temperature increasing from 140 ℃ to 180 ℃ and then decrease at 200 ℃, giving an average grain size of 0.81 μm and a largest grain size of about 2 μm at 180 ℃. The defect density of perovskite film is deduced from the space charge limited current model,showing that it decreases from 5.90×10~(16) cm~(–3) at 140 ℃ to 2.66×10~(16) cm~(–3) at 180 ℃. Photovoltaic devices with structure FTO/TiO_2/C_(60)/MAPbI_3/spiro-OMeTAD/Au are fabricated to demonstrate the performance. It is found that the devices with an active area of 0.045 cm~2 show that with the increase of grain size, the average PCE increases from 14.00% to 17.42%, and the best device shows that its PCE is 17.80% with 4.04% hysteresis index. To show the possibility of scaling up, we fabricate a uniform perovskite thin film with an area of about 72 cm~2, and a device with an active area of 1 cm~2, which gives a PCE of 13.17% in reverse scan. In summary,our research provides a method of regulating the grain size for the vapor deposition, which can improve device performance by reducing the trap density in perovskite film for suppressing the carrier recombination in grain boundary. Meanwhile, we prepare high performance devices and large area thin films, showing their potential in large area device fabrication and applications.
引文
[1]Yin W J,Shi T,Yan Y 2014 Adv.Mater.26 4653
[2]De Wolf S,Holovsky J,Moon S J,Loper P,Niesen B,Ledinsky M,Haug F J,Yum J H,Ballif C 2014 J.Phys.Chem.Lett.5 1035
[3]Green M A,Ho-Baillie A,Snaith H J 2014 Nature Photon.8506
[4]Kojima A,Teshima K,Shirai Y,Miyasaka T 2009 J.Am.Chem.Soc.131 6050
[5]Correa-Baena J P,Saliba M,Buonassisi T,Gr?tzel M,Abate A,Tress W,Hagfeldt A 2017 Sicence 358 739
[6]Wu C C,Sun W H,Chen Z J,Xiao L X 2017 Chin.Sci.Bull.62 1457(in Chinese)[吴存存,孙伟海,陈志坚,肖立新2017科学通报62 1457]
[7]Yang X D,Chen H,Bi E B,Han L Y 2015 Acta Phys.Sin.64 038404(in Chinese)[杨旭东,陈汉,毕恩兵,韩礼元2015物理学报64 038404]
[8]Yang Y G,Yin G Z,Feng S L,Li M,Ji G W,Song F,Wen W,Gao X Y 2017 Acta Phys.Sin.66 018401(in Chinese)[杨迎国,阴广志,冯尚蕾,李萌,季庚午,宋飞,文闻,高兴宇2017物理学报66 018401]
[9]Liu M,Johnston M B,Snaith H J 2013 Nature 501 395
[10]Chen Q,Zhou H P,Hong Z R,Luo S,Duan H S,Wang H H,Liu Y S,Li G,Yang Y 2014 J.Am.Chem.Soc.136 622
[11]Hsiao S Y,Lin H L,Lee W H,Tsai W L,Chiang K M,Liao W Y,Zheng C,Wu R Z,Chen C Y,Lin H W 2016 Adv.Mater.28 7013
[12]Chen C Y,Lin H Y,Chiang K M,Tsai W L,Huang Y C,Tsao C S,Lin H W 2017 Adv.Mater.29 1605290
[13]Long M Z,Zhang T K,Liu M Z,Chen Z F,Wang C,Xie WG,Xie F Y,Chen J,Li G,Xu J B 2018 Adv.Mater.301801562
[14]Tong G Q,Li H,Li G P,Zhang T,Li C D,Yu L W,Xu J,Jiang Y,Shi Y,Chen K J 2018 Nano Energy 48 536
[15]Zhu X J,Yang D,Yang R X,Yang B,Yang Z,Ren X D,Zhang J,Niu J Z,Feng J S,Liu S Z 2017 Nanoscale 9 12316
[16]Niu T Q,Lu J,Munir R,Li J B,Barrit D,Zhang X,Hu H L,Yang Z,Amassian A,Zhao K,Liu S Z 2018 Adv.Mater.301706576
[17]Seok S I,Kim E K,Noh J H 2017 Science 356 1376
[18]Li X,Chen C C,Cai M,Hua X,Xie F,Liu X,Hua J,Long YT,Tian H,Han L 2018 Adv.Energy Mater.8 1800715
[19]Han Q,Bai Y,Liu J,Du K Z,Li T,Ji D,Zhou Y,Cao C,Shin D,Ding J,Franklin A D,Glass J T,Hu J,Therien M J,Liu J,Mitzi D B 2017 Energy Environ.Sci.10 2365
[20]Wang D,Zhu H M,Zhou Z M,Wang Z W,LüS L,Pang SP,Cui G L 2015 Acta Phys.Sin.64 038403(in Chinese)[王栋,朱慧敏,周忠敏,王在伟,吕思刘,逄淑平,崔光磊2015物理学报64 038403]
[21]Du X,Chen S,Lin D X,Xie F Y,Chen J,Xie W G,Liu P Y2018 Acta Phys.Sin.67 098801(in Chinese)[杜相,陈思,林东旭,谢方艳,陈建,谢伟广,刘彭义2018物理学报67 098801]
[22]Tavakoli M M,Simchi A,Mo X,Fan Z 2017 Mater.Chem.Front.1 1520
[23]Yue S Z,Liu K,Xu R,Li M C,Azam M,Ren K,Liu J,Sun Y,Wang Z J,Cao D W,Yan X H,Qu S C,Lei Y,Wang Z G2017 Energy Environ.Sci.10 2570
[24]Zhang T K,Long M Z,Qin M C,Lu X H,Chen S,Xie F Y,Gong L,Chen J,Chu M,Miao Q,Chen Z F,Xu W Y,Liu P Y,Xie W G,Xu J B 2018 Joule 2 1
[25]Zhang T K,Long M Z,Yan K Y,Qin M C,Lu X H,Zeng XL,Cheng C M,Wong K S,Liu P Y,Xie W G,Xu J B 2017Adv.Energy Mater.7 1700118
[26]Shao Y C,Fang Y J,Li T,Wang Q,Dong Q F,Deng Y H,Yuan Y B,Wei H T,Wang M Y,Gruverman A,Shield J,Huang J S 2016 Energy Environ.Sci.9 1752
[2]De Wolf S,Holovsky J,Moon S J,Loper P,Niesen B,Ledinsky M,Haug F J,Yum J H,Ballif C 2014 J.Phys.Chem.Lett.5 1035
[3]Green M A,Ho-Baillie A,Snaith H J 2014 Nature Photon.8506
[4]Kojima A,Teshima K,Shirai Y,Miyasaka T 2009 J.Am.Chem.Soc.131 6050
[5]Correa-Baena J P,Saliba M,Buonassisi T,Gr?tzel M,Abate A,Tress W,Hagfeldt A 2017 Sicence 358 739
[6]Wu C C,Sun W H,Chen Z J,Xiao L X 2017 Chin.Sci.Bull.62 1457(in Chinese)[吴存存,孙伟海,陈志坚,肖立新2017科学通报62 1457]
[7]Yang X D,Chen H,Bi E B,Han L Y 2015 Acta Phys.Sin.64 038404(in Chinese)[杨旭东,陈汉,毕恩兵,韩礼元2015物理学报64 038404]
[8]Yang Y G,Yin G Z,Feng S L,Li M,Ji G W,Song F,Wen W,Gao X Y 2017 Acta Phys.Sin.66 018401(in Chinese)[杨迎国,阴广志,冯尚蕾,李萌,季庚午,宋飞,文闻,高兴宇2017物理学报66 018401]
[9]Liu M,Johnston M B,Snaith H J 2013 Nature 501 395
[10]Chen Q,Zhou H P,Hong Z R,Luo S,Duan H S,Wang H H,Liu Y S,Li G,Yang Y 2014 J.Am.Chem.Soc.136 622
[11]Hsiao S Y,Lin H L,Lee W H,Tsai W L,Chiang K M,Liao W Y,Zheng C,Wu R Z,Chen C Y,Lin H W 2016 Adv.Mater.28 7013
[12]Chen C Y,Lin H Y,Chiang K M,Tsai W L,Huang Y C,Tsao C S,Lin H W 2017 Adv.Mater.29 1605290
[13]Long M Z,Zhang T K,Liu M Z,Chen Z F,Wang C,Xie WG,Xie F Y,Chen J,Li G,Xu J B 2018 Adv.Mater.301801562
[14]Tong G Q,Li H,Li G P,Zhang T,Li C D,Yu L W,Xu J,Jiang Y,Shi Y,Chen K J 2018 Nano Energy 48 536
[15]Zhu X J,Yang D,Yang R X,Yang B,Yang Z,Ren X D,Zhang J,Niu J Z,Feng J S,Liu S Z 2017 Nanoscale 9 12316
[16]Niu T Q,Lu J,Munir R,Li J B,Barrit D,Zhang X,Hu H L,Yang Z,Amassian A,Zhao K,Liu S Z 2018 Adv.Mater.301706576
[17]Seok S I,Kim E K,Noh J H 2017 Science 356 1376
[18]Li X,Chen C C,Cai M,Hua X,Xie F,Liu X,Hua J,Long YT,Tian H,Han L 2018 Adv.Energy Mater.8 1800715
[19]Han Q,Bai Y,Liu J,Du K Z,Li T,Ji D,Zhou Y,Cao C,Shin D,Ding J,Franklin A D,Glass J T,Hu J,Therien M J,Liu J,Mitzi D B 2017 Energy Environ.Sci.10 2365
[20]Wang D,Zhu H M,Zhou Z M,Wang Z W,LüS L,Pang SP,Cui G L 2015 Acta Phys.Sin.64 038403(in Chinese)[王栋,朱慧敏,周忠敏,王在伟,吕思刘,逄淑平,崔光磊2015物理学报64 038403]
[21]Du X,Chen S,Lin D X,Xie F Y,Chen J,Xie W G,Liu P Y2018 Acta Phys.Sin.67 098801(in Chinese)[杜相,陈思,林东旭,谢方艳,陈建,谢伟广,刘彭义2018物理学报67 098801]
[22]Tavakoli M M,Simchi A,Mo X,Fan Z 2017 Mater.Chem.Front.1 1520
[23]Yue S Z,Liu K,Xu R,Li M C,Azam M,Ren K,Liu J,Sun Y,Wang Z J,Cao D W,Yan X H,Qu S C,Lei Y,Wang Z G2017 Energy Environ.Sci.10 2570
[24]Zhang T K,Long M Z,Qin M C,Lu X H,Chen S,Xie F Y,Gong L,Chen J,Chu M,Miao Q,Chen Z F,Xu W Y,Liu P Y,Xie W G,Xu J B 2018 Joule 2 1
[25]Zhang T K,Long M Z,Yan K Y,Qin M C,Lu X H,Zeng XL,Cheng C M,Wong K S,Liu P Y,Xie W G,Xu J B 2017Adv.Energy Mater.7 1700118
[26]Shao Y C,Fang Y J,Li T,Wang Q,Dong Q F,Deng Y H,Yuan Y B,Wei H T,Wang M Y,Gruverman A,Shield J,Huang J S 2016 Energy Environ.Sci.9 1752