Characterizing the Influence of Charge Extraction Layers on the Performance of Triple‐Cation Perovskite Solar Cells

Abstract

Selecting suitable charge transport layers and suppressing non‐radiative recombination at interfaces with the absorber layer is vital for maximizing the efficiency of halide perovskite solar cells. In this study, high‐quality perovskite thin films and devices are fabricated with different fullerene‐based electron transport layers and different self‐assembled monolayers as hole transport layers. Then, a comparative study of a significant variety of different electrical, optical, and photoemission‐based characterization techniques is performed to quantify the properties of the solar cells, individual layers, and, importantly, the interfaces between them. In addition, the limitations and problems of the different measurements, the insights gained by combining different methods, and the different strategies for extracting information from the experimental raw data, are highlighted.

A Universal Strategy of Perovskite Ink ‐ Substrate Interaction to Overcome the Poor Wettability of a Self‐Assembled Monolayer for Reproducible Perovskite Solar Cells

“…Besides various perovskite compositions, the perovskite ink-substrate interaction strategy can also be applied to obtain a uniform perovskite layer on various hydrophobic HTLs, for instance, we obtained a uniform perovskite layer on widely used hydrophobic PTAA. [94] These results evidence that a high-quality thin film of different perovskite compositions can be obtained on hydrophobic Me-4PACz by our perovskite ink-substrate interaction strategy, highlighting its universality. Last, we studied the long-term stability of triple cation perovskite solar cells from the triple co-solvent-based perovskite ink.…”

“…Besides various perovskite compositions, the perovskite ink–substrate interaction strategy can also be applied to obtain a uniform perovskite layer on various hydrophobic HTLs, for instance, we obtained a uniform perovskite layer on widely used hydrophobic PTAA. [ 94 ]…”

Hole Transporting Bilayers for Efficient Micrometer‐Thick Perovskite Solar Cells

“…Therefore, a reasonable bulk lifetime must be assumed or measured. As we have recently shown [54,55] bulk lifetimes in halide perovskite films are often a strong function of carrier density or Fermi-level splitting, we can only apply the above approach if we consider all lifetimes and recombination velocities to be a function of ΔE F . The physical reason for this necessity is that, in the presence of a significant density of shallow traps, the SRH formalism predicts that the decay time 𝜏 diff in an intrinsic semiconductor continuously changes with carrier density.…”

Small molecule-incorporated SnO2 layer for efficient perovskite solar cells

“…5 However, the non-radiative recombination caused by PSC interface defects hinders any further improvement in the PCE and stability. 6–9 The interface designs of the electron transport layer (ETL)/perovskite are important to realize highly efficient and stable PSCs. 10–14…”

“…5 However, the non-radiative recombination caused by PSC interface defects hinders any further improvement in the PCE and stability. [6][7][8][9] The interface designs of the electron transport layer (ETL)/perovskite are important to realize highly efficient and stable PSCs. [10][11][12][13][14] Currently, various modifiers are used to reduce defects in the ETL/perovskite interface, [15][16][17] such as Lewis acid-based compounds 18 and cations, 19 and research has been conducted to improve their interfacial properties.…”