ABSTRACT
CsPbI3 perovskite receives tremendous attention for photovoltaic applications due to its ideal band gap and good thermal stability. However, CsPbI3 perovskite solar cells (PSCs) significantly suffer from photovoltage deficits because of serious interfacial energy losses within the PSCs, which to a large extent affects the photovoltaic performance of PSCs. Herein, a dipolar chemical bridge (DCB) is constructed between the perovskite and TiO2 layers to lower interfacial energy losses and thus improve the charge extraction of PSCs. The results reveal that the DCB could form a beneficial interfacial dipole between the perovskite and TiO2 layers, which could optimize the interfacial energetics of perovskite/TiO2 layers and thus improve the energy level alignment within the PSCs. Meanwhile, the constructed DCB could also simultaneously passivate the surface defects of perovskite and TiO2 layers, greatly lowering interfacial recombination. Consequently, the photovoltage deficit of CsPbI3 PSCs is largely reduced, leading to a record efficiency of 21.86 % being realized. Meanwhile, the operation stability of PSCs is also largely improved due to the high-quality perovskite films with released interfacial tensile strain being obtained after forming the DCB within the PSCs.
ABSTRACT
[This corrects the article DOI: 10.3389/ijph.2022.1605124.].
ABSTRACT
Objectives: Although the evidence from numerous longitudinal studies has indicated a remarkable change in cognitive function (CF) and depressive symptoms (DS) over time, the parallel latent growth curve model (LGCM) has seldom been used to simultaneously investigate the relationship between their change trajectories. This study aimed to examine whether a change in DS was associated with CF over time using an LGCM. Methods: Data were collected from the Chinese Longitudinal Healthy Longevity Survey's 2011, 2014, and 2018 waves. A parallel LGCM examined the association between CF and DS. Results: The multivariate conditioned model's goodness of fit supported the validity of the longitudinal model (Tucker-Lewis index [TLI] = 0.90, comparative fit index [CFI] = 0.96, root mean square error of approximation [RMSEA] = 0.04). The results showed that the CF intercept was positively to the DS slope (ß = 0.42, p = 0.004). The CF and DS slopes were significantly linked (ß = -0.65, p = 0.002). Conclusion: The findings expand the knowledge about CF's effect on DS in older adults.
Subject(s)
Cognition , Depression , Aged , Depression/epidemiology , Humans , Longitudinal StudiesABSTRACT
Formamidinium lead triiodide (FAPbI3) perovskite quantum dots (PQDs) show great advantages in photovoltaic applications due to their ideal bandgap energy, high stability and solution processability. The anti-solvent used for the post-treatment of FAPbI3 PQD solid films significantly affects the surface chemistry of the PQDs, and thus the vacancies caused by surface ligand removal inhibit the optoelectronic properties and stability of PQDs. Here, we study the effects of different anti-solvents with different polarities on FAPbI3 PQDs and select a series of organic molecules for surface passivation of PQDs. The results show that methyl acetate could effectively remove surface ligands from the PQD surface without destroying its crystal structure during the post-treatment. The benzamidine hydrochloride (PhFACl) applied as short ligands of PQDs during the post-treatment could fill the A-site and X-site vacancies of PQDs and thus improve the electronic coupling of PQDs. Finally, the PhFACl-based PQD solar cell (PQDSC) achieves a power conversion efficiency of 6.4%, compared to that of 4.63% for the conventional PQDSC. This work provides a reference for insights into the surface passivation of PQDs and the improvement in device performance of PQDSCs.
ABSTRACT
The interfacial properties of the perovskite photovoltaic layer and electron transport layer (ETL) are critical to minimize energy losses of perovskite solar cells (PSCs) induced by interfacial recombination. Herein, the interface engineering of the SnO2/FAPbI3 perovskite using PbX2 (X = Cl, Br, or I) as an interlayer is extensively studied using first-principles calculations. The results reveal that the thickness of the PbI2 interlayer needs to be finely controlled, which may limit charge transport if there is a large amount of PbI2 precipitation at the interface. The high lattice mismatch of the PbBr2 with the SnO2/FAPbI3 interface makes PbBr2 an unfavorable passivation material. Due to the strong coupling of the PbCl2 with both SnO2 and FAPbI3, an efficient electron transport pathway could be built after applying PbCl2 as an interlayer. Meanwhile, the PbCl2 interlayer could also effectively passivate interface defects, therefore lowering the energy losses of PSCs.
