Effect of Solvent Residue in the Thin-Film Fabrication on Perovskite Solar Cell Performance

Abstract

Organic−inorganic Pb-based halide perovskite photoelectrical materials, especially perovskite solar cells (PSCs), have attracted attention due to the significant efforts in improving the power conversion efficiency (PCE) to above 25%. However, the stability issue of the PSCs restricts their further development for commercialization. Strategies are designed to keep moisture and oxygen out of the perovskite films, such as additive, surface passivation, and solvent engineering; however, usually, the corrosion of active films by the residual solvent is mostly ignored. Solvent residue is the paramount factor influencing the stability of the perovskite film prepared by the solution method, and most solvents can be easily absorbed and accelerate the perovskite film decomposition. Here, we studied the residual solvent effect on two kinds of perovskite films obtained by different annealing processes: hot air annealing and hot bench annealing. Several detection techniques were used to study the performance of two different annealing methods, including time-of-flight secondary ion mass spectrometry (ToF-SIMS), thermogravimetric analysis (TGA), and field-emission scanning electron microscopy (FESEM). The perovskite film obtained by hot air annealing shows less residual solvent and better device performance than the hot bench annealing method. This method is expected to provide insight into reducing solvent residue to improve the stability of the PSCs, especially for future commercialization.

Efficient and stable formamidinium–caesium perovskite solar cells and modules from lead acetate-based precursors

“…[26][27][28][29] The addition of these solvents has been found to be detrimental to the device stability as they can easily be trapped in the films and lead to the formation of voids at the perovskite substrate interface due to their high boiling points and strong coordination ability. [30][31][32][33][34] Although, there is still an ongoing debate in the literature on the impact of these voids with a recent study suggesting that they are not necessarily detrimental to the device stability. 35 By using PbAc 2 as the lead source these problems can be avoided as neither an antisolvent nor the addition of a high-boiling point solvent, such as DMSO or NMP, is required to control the crystallization.…”

Effective Utilization of Synthesized FeS2 for Improving Output Performance of Polycrystalline Silicon Solar Cell

“…From the I-V characteristic curve, the F3 sample holds denser and more uniform coatings of materials. e coating thickness and material distribution were clearly identified using the FESEM technique [23][24][25].…”

Designed multi-layer buffer for high-performance semitransparent wide-bandgap perovskite solar cells

“…The trap-state density is proportional to the trap-filled limit voltage (V TFL ), which is a turning point between the linear Ohmic region and the nonlinear trapfilling region in the current density-voltage curve. [53][54][55] Among three kinds of devices, the device with the ZnO/BCP/Ag multi-layer buffer presented the smallest V TFL value of 0.122 V, corresponding to the lowest trap-state density and minimum of non-radiative recombination. To sum up, the multi-layer buffer facilitated carrier extraction and reduced non-radiative recombination between the electron transport layer and TCO layer, resulting in the performance improvement of ST-PSCs.…”