Impact of a Spun-Cast MoO_x Layer on the Enhanced Moisture Stability and Performance-Limiting Behaviors of Perovskite Solar Cells

Abstract

Organic–inorganic perovskite solar cells (PSCs), which have good environmental durability, are of great interest for practical applications. In this work, we show that a solution-processed MoO x layer acts as a buffer layer against high moisture stress to suppress defects in the perovskite and as a hole transport layer. The inversion of the photoinduced charge migration behaviors, that is, the electron preferentially moving toward the surface when MoO x is directly deposited onto the perovskite, is found to cause a significant loss in device functionality. The deposition of MoO x onto spiro-OMeTAD results in a lower photocurrent density–voltage (J–V) hysteresis behavior, a greatly enhanced electrical conductivity, and a significantly stabilized power conversion efficiency (PCE) when compared with those of devices without the MoO x layer. More importantly, the PCEs of the MoO x -based devices are retained at over 85% of their initial value, while only 75% is retained for a reference cell. This work highlights the facial fabrication approach of the solution-based MoO x layer and provides experimental evidence of the photogenerated charge migration behaviors on the perovskite/MoO x interface. This information would be beneficial for the further design and development of PSC technology.

Simultaneous Surface Modification and Defect Passivation on Tin Oxide–Perovskite Interfaces using Pseudohalide Salt of Sodium Tetrafluoroborate

“…[52] Compared to the phase-shifted (by 90°) (Y) signals, the relatively large in-phase (X) signals provide information on faster responses of the SPV signals than the responses obtained by changing the modulation period for the movement of photogenerated charges. [53] Figure 6c shows an overview of the X and Y signals obtained from the perovskite film deposited on the surface of SnO 2 w/ 0.05-M NaBF 4 (blue) and w/o (black) NaBF 4 coating. Perovskite films exhibit X signals with a positive sign, reaching a maximum value at a similar photon energy of 1.59 eV, corresponding to the bandgap of the fabricated perovskite.…”

“…[ 52 ] Compared to the phase‐shifted (by 90°) (Y) signals, the relatively large in‐phase (X) signals provide information on faster responses of the SPV signals than the responses obtained by changing the modulation period for the movement of photogenerated charges. [ 53 ]…”

Advances in Encapsulations for Perovskite Solar Cells: From Materials to Applications

“…Inserting an insulating layer between the metal electrode and the HTL can effectively suppress the diffusion of metal atoms. [71,115,116] In addition, the wide range application of carbon electrodes with low cost and high stability can effectively solve the degradation caused by the diffusion of metal atoms. [117,118]…”

“…When 45 nm SiO 2 is applied to CH 3 NH 3 PbI 3 , the device's lifetime is extended by about 60 times, and 300 nm SiO 2 is applied to triple‐cation perovskite material, the lifetime of the device is extended by about 600 times. In addition, there are other inorganic materials as encapsulation layers for PSCs, such as MoO x , [ 116 ] Bi, [ 133 ] etc.…”

Facilitating Electron Transport in Perovskite Solar Cells Through Tailored SnO2 Film Composition

“…[ 12,13 ] Different preparation methods for SnO 2 include the popular SnO 2 nanoparticle, chemical methods, and chemical bath deposition (CBD‐SnO 2 ). [ 14–16 ] An innovative approach by Yang et al involved introducing EDTA into the SnO 2 nanoparticle solution, effectively enhancing the conductivity and energy level of SnO 2 , resulting in an impressive efficiency of 21.6%. [ 17 ] Similarly, Kim et al achieved a notable efficiency of 25.7% by utilizing SnO 2 quantum dots stabilized with polyacrylic acid.…”