Chen Hui, Luo Qiang, Liu Tao, Tai Meiqian, Lin Jing, Murugadoss Vignesh, Lin Hong, Wang Jinshu, Guo Zhanhu, Wang Ning
State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China.
ACS Appl Mater Interfaces. 2020 Mar 25;12(12):13941-13949. doi: 10.1021/acsami.9b23255. Epub 2020 Mar 16.
Organic-inorganic hybrid perovskite solar cells (PSCs), as the most rapidly developing next-generation thin-film photovoltaic technology, have attracted extensive research interest, yet their efficiency, scalability, and durability remain challenging. α-FeO could be used as an electron transporting layer (ETL) of planar PSCs, which exhibits a much higher humidity and UV light-stability compared to TiO-based planar PSCs. However, the photovoltaic conversion efficiency (PCE) of the FeO-based device was still below 15% because of poor interface contact between α-FeO and perovskite and poor crystal quality of perovskites. In this work, we have engineered the interfaces throughout the entire solar cell incorporating N, S co-doped graphene quantum dots (NSGQDs). The NSGQDs played remarkable multifunctional roles: (i) facilitated the perovskite crystal growth; (ii) eased charge extraction at both anode and cathode interfaces; and (iii) induced the defect passivation and suppressed the charge recombination. When assembled with a α-FeO ETL, the planar PSCs exhibited a significantly increased efficiency from 14 to 19.2%, with concomitant reductions in hysteresis, which created a new record of the PCE for FeO-based PSCs to date. In addition, PSCs with the entire device interfacial engineering showed an obviously improved durability, including prominent humidity, UV light, and thermal stabilities. Our interfacial engineering methodology graphene quantum dots represents a versatile and effective way for building high efficiency as well as durable PSCs.
有机-无机杂化钙钛矿太阳能电池（PSCs）作为发展最为迅速的下一代薄膜光伏技术，已引起广泛的研究兴趣，但其效率、可扩展性和耐久性仍具有挑战性。α-FeO可作为平面PSCs的电子传输层（ETL），与基于TiO的平面PSCs相比，它表现出更高的湿度和紫外光稳定性。然而，由于α-FeO与钙钛矿之间的界面接触不良以及钙钛矿的晶体质量较差，基于FeO的器件的光电转换效率（PCE）仍低于15%。在这项工作中，我们通过引入N、S共掺杂的石墨烯量子点（NSGQDs）对整个太阳能电池的界面进行了工程设计。NSGQDs发挥了显著的多功能作用：（i）促进钙钛矿晶体生长；（ii）在阳极和阴极界面处均便于电荷提取；（iii）诱导缺陷钝化并抑制电荷复合。当与α-FeO ETL组装时，平面PSCs的效率从14%显著提高到19.2%，同时滞后现象减少，这创造了迄今为止基于FeO的PSCs的PCE新记录。此外，采用整个器件界面工程的PSCs的耐久性明显提高，包括显著的湿度、紫外光和热稳定性。我们的界面工程方法——石墨烯量子点，代表了一种构建高效且耐用的PSCs的通用且有效的方法。
