Stable perovskite solar cells with 25.17% efficiency enabled by improving crystallization and passivating defects synergistically

Abstract

The film quality of light absorber is the key factor that limits the efficiency and stability of perovskite solar cells (PSCs). Herein, a new ammonium salt of 2-amidinopyrimidine hydrochloride (APC)...

Room-temperature electrochemically deposited polycrystalline SnO2 with adjustable work function for high-efficiency perovskite solar cells

“…† The device based on SnO 2 (pH = 1) shows a larger recombination resistance (R rec ), which suggests less charge recombination in it. This is consistent with the device efficiency 42.…”

Over 25% efficiency and stable bromine-free RbCsFAMA-based quadruple cation perovskite solar cells enabled by an aromatic zwitterion

“…6,7 However, the relatively large ionic radius of FA makes FAPbI 3 exhibit a non-ideal tolerance factor, 8 leading to phase transformation from the a to the d phase when the temperature is below 150 °C, or exposed to a humid atmosphere, light and heat. 9 To overcome these drawbacks, composition engineering, [10][11][12] additives, [13][14][15][16] and low-dimensional perovskites 17 have been adopted to stabilize the crystal structure, modulate the lm quality and depress the trap-state of FAbased perovskites. Among those types of perovskites with different compositions, multi-cation FA-based perovskites, such as CsFAMA, 18 CsRbFA, 19 and RbCsFAMA, 20,21 show improved device performance and stability in comparison with pure FAbased or pure MA-based perovskites.…”

Orotic Acid as a Bifunctional Additive for Regulating Crystallization and Passivating Defects toward High-Performance Formamidinium–Cesium Perovskite Solar Cells

“…The resonances at 6.00, 10.88, 11.32, and 14.44 ppm corresponded to hydrogens in −CCH–, −C–NH-CO–, −CO-NH-CO–, and −COOH in ORO. The proton signal of the −COOH in ORO shifted from 10.88 to 10.81, and the proton signals of N–H shifted from 11.32 and 14.44 to 11.27 and 13.95, respectively, demonstrating the formation of hydrogen bonds between the ORO and FAI. , The UV–vis absorption spectra of ORO, FAI, and the mixed ORO/FAI solution are shown in Figure d. The redshift of the absorption onset after mixing ORO with FAI also indicated the existence of hydrogen bonds .…”

“…The proton signal of the −COOH in ORO shifted from 10.88 to 10.81, and the proton signals of N–H shifted from 11.32 and 14.44 to 11.27 and 13.95, respectively, demonstrating the formation of hydrogen bonds between the ORO and FAI. , The UV–vis absorption spectra of ORO, FAI, and the mixed ORO/FAI solution are shown in Figure d. The redshift of the absorption onset after mixing ORO with FAI also indicated the existence of hydrogen bonds . Therefore, ORO could not only coordinate with Pb 2+ but also form hydrogen bonds with I – , leading to a slow perovskite crystallization rate .…”

“…Taking into account the XPS and FTIR results, it may be concluded that the Lewis base carboxyl coordinated with Pb 2+ using the O-atom rather than the N-atom in the amide group because of the strong electron-withdrawing property of carbonyl . It may be noted that while lead ions can interact with pyridine nitrogen that has a good coordinating ability, the amide N-atom in ORO is a relatively weak base with a poor coordinating ability, and hence, the coordination of Pb 2+ with the O atom would be dominant in the current situation.…”