Reduced Surface Hydroxyl and Released Interfacial Strain by Inserting CsF Anchor Interlayer for High‐Performance Perovskite Solar Cells

Abstract

Defects passivation strategy for the atop perovskite films is widely investigated, while the buried interface between the tin oxide electron transport layer and the perovskite active layer should gain more attention since the interfacial strains and surface hydroxyl are inevitable during the fabrication process which would affect the efficiency and stability of the fabricated perovskite devices. Herein, the CsF interlayer between SnO2 and perovskite film is adopted to release the interfacial strain and decrease the surface hydroxyl through the atomic interaction and chemical doping. Furthermore, the CsF can tailor the energy level of SnO2 for a more favorable alignment to reduce the energy loss and improve charge extraction. Correspondingly, the perovskite photovoltaic devices with the efficiency of 23.13% are achieved. Moreover, CsF‐doped devices demonstrate enhanced stability, which could maintain 87% of its initial efficiency after 1000 h under environmental storage. The developed CsF interfacial engineering provides a promising strategy for the interfacial modulation.

Tri(4-trifluoromethylphenyl)phosphine-Modified Hole-Transport Material PTAA to Improve the Performance of Perovskite Solar Cells

“…where μ, ε, ε 0 , J, L, V app , V r , and V bi are carrier mobility, vacuum permittivity, the relative dielectric constant, current density, the thickness of films, applied voltage, voltage drop, and built-in voltage, respectively. 27,28 Similarly, compared with undoped PTAA films (2.01 × 10 −3 cm −2 V −1 S −1 ) and Li-doped PTAA films (3.95 × 10 −3 cm −2 V −1 S −1 ), 343FP-doped PTAA films (4.46 × 10 −3 cm −3 V −1 S −1 ) exhibited the highest mobility.…”

“…The conductivity of the undoped PTAA film, Li-doped PTAA film, and 343FP-doped PTAA film are 3.527 × 10 –6 , 5.923 × 10 –6 , and 6.708 × 10 –6 S·cm –1 , respectively. Figure b shows the corresponding mobility curve, and the electron mobility is calculated by the following equation: where μ, ε, ε 0 , J , L , V app , V r , and V bi are carrier mobility, vacuum permittivity, the relative dielectric constant, current density, the thickness of films, applied voltage, voltage drop, and built-in voltage, respectively. , Similarly, compared with undoped PTAA films (2.01 × 10 –3 cm –2 V –1 S –1 ) and Li-doped PTAA films (3.95 × 10 –3 cm –2 V –1 S –1 ), 343FP-doped PTAA films (4.46 × 10 –3 cm –3 V –1 S –1 ) exhibited the highest mobility. The results show that 343FP can indeed effectively improve the conductivity of the PTAA film and increase the efficiency of photogenerated carrier migration from the PSK layer to the HTL, which is consistent with the results of PL spectroscopy, proving the stronger PL quenching effect in the device.…”

Strain Effects on Flexible Perovskite Solar Cells

“…The corresponding adjustment of the preparation technology is an important way to control this strain. [126][127][128] Zhao et al [129] did not use the traditional high-temperature annealing process, but grew the MAPbI 3 perovskite film at room temperature in a vacuum atmosphere for 3 days. The authors found no stress in these films, proving that temperature is the key factor for the lattice strain in the perovskite layer.…”

Inkjet-printed SnO x as an effective electron transport layer for planar perovskite solar cells and the effect of Cu doping

“…Low-temperature processed SnO 2 ETLs have been reported to deliver high device performance [14][15][16], even superior to that of their high-temperature processed counterparts [17,18]. Up to now, the main strategy for boosting the performance and stability of SnO 2 based devices has been to suppress energy loss within SnO 2 [19,20] or at the ETL/perovskite interface [21][22][23]. Doping is a direct and effective method of modifying the properties of SnO 2 , such as the conductivity and work function, which can facilitate electron extraction and transport [24].…”