Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critical...Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critically compromise the device efficiency and stability.Phosphonic acid-based multifunctional molecules,mainly as self-assemble monolayer,have recently been demonstrated to be useful in improving the device performance of the inverted PSCs.Herein,we designed and synthesized a new multifunctional molecule,(2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid(M28)as additive in perovskite precursor solution to fabricate high-efficiency and stable inverted PSCs.Through spontaneous segregation toward the buried interface and grain boundaries(GBs),M28 affords threefold roles in enhancing device performance:(1)slowing the crystallization rate and enlarging the grain sizes to improve the perovskite film quality,(2)passivating the defects at buried interface and GBs to suppress charge recombination,(3)inducing an extra electric field at the buried interface through p-type doping to promote hole transport.The resulting devices thus achieved a remarkable power conversion efficiency of 25.96%and impressive long-term operational stability:maintaining 80%of their initial efficiency after 1500 h tracking at the maximum power point.This work emphasizes the importance of exploration of new types of functional molecules in advancing PSCs.展开更多
基金financially supported by the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302AO370013)Yunnan Provincial Science and Technology Project of Key Research and Development Plan(202403AC100030)+2 种基金Yunnan Fundamental Research Projects(202401AU070200,202501AT070204)State Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy(Innovation Fund Project SKLPCU24OP004)Natural Science Founda-tion of Xinjiang Uygur Autonomous Region(2022D01D079)。
文摘Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critically compromise the device efficiency and stability.Phosphonic acid-based multifunctional molecules,mainly as self-assemble monolayer,have recently been demonstrated to be useful in improving the device performance of the inverted PSCs.Herein,we designed and synthesized a new multifunctional molecule,(2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid(M28)as additive in perovskite precursor solution to fabricate high-efficiency and stable inverted PSCs.Through spontaneous segregation toward the buried interface and grain boundaries(GBs),M28 affords threefold roles in enhancing device performance:(1)slowing the crystallization rate and enlarging the grain sizes to improve the perovskite film quality,(2)passivating the defects at buried interface and GBs to suppress charge recombination,(3)inducing an extra electric field at the buried interface through p-type doping to promote hole transport.The resulting devices thus achieved a remarkable power conversion efficiency of 25.96%and impressive long-term operational stability:maintaining 80%of their initial efficiency after 1500 h tracking at the maximum power point.This work emphasizes the importance of exploration of new types of functional molecules in advancing PSCs.
