Quantum well growth management of energy transfer pathways in quasi-two-dimensional perovskite solar cells

• Compared with three-dimensional PSCs , two-dimensional (2D) perovskite solar cells (PSCs) exhibit better stability. However, fundamental problems remain with the chemical phase space in 2D perovskite frameworks. Here, Chen Yiwang, Hu Ting and others from Nanchang University proposed that alternating cations in the interlayer space of 2D perovskites (GA(MA)nPbnI3 n+1) are regulated by using potassium salts to control the assembly behavior of colloidal particles and manage the growth of quantum wells.

  
  

  The strong affinity between spacer cations and sulfonates can slow down the insertion of organic spacer cations and provide a time window for the insertion of MA, which is beneficial to the formation of high-n phase and facilitates charge transfer. During the crystallization process, potassium salts are extruded to the grain boundaries and produce a passivation effect. In this case, the ion migration channel and the entrance of water and oxygen are cut off, which is beneficial to the stability of PSCs.

  
  

  It is understood that this work achieved a power conversion efficiency of 20.90%, which is the highest among all reported GA(MA)nPbnI3n+1 PCE perovskites and large-area devices (1.01 cm2) showing a high efficiency of 18.73%. In addition, these devices have good humidity stability.

  
  

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• Y. Wang, D. Li, Z. Xing, J. Li, X. Hu, T. Hu, Y. Chen, Quantum Well Growth Management to Smooth the Energy Transfer Pathway for Quasi-2D Perovskite Solar Cells. Adv. Funct. Mater. 2024, 2401203.

  
  

  https://doi.org/10.1002/adfm.202401203