Amino‐Linked Conjugated Tetrazole Ring Passivation Strategy for Air‐Processed Perovskite Cells with Predominant Stability and Efficiency

Abstract

Perovskite solar cells (PSCs) develop rapidly with certified efficiency over 25.5 %, but there are remaining problems such as defects‐induced recombination and degradation throughout the whole device. Functional organic small molecule passivation strategies are diverse and efficient, enhancing the efficiency and stability of PSCs. Here, 5‐aminotetrazole (5ATZ) was introduced for the first time as an effective passivator, where −NH2 and −NH as active sites interacted with the Pb and I related to vacancy defects in perovskites, anchoring defects and preventing further unavoidable ion migration and device degradation. Furthermore, the extensive π‐electron delocalization around the tetrazole conjugated ring significantly promoted the charge transfer. Therefore, the 5ATZ‐processed PSCs provided enhanced voltage and current, showed superior 19.75 % power conversion efficiency with excellent performance and improved stability, and demonstrated one of the best performances in all‐air preparation to date. The simultaneous multi‐effect passivation strategy of vacancy defects in perovskites will contribute to eliminate obstacles on the road to commercialization of PSCs.

Solvent-assisted preparation of low-temperature SnO2 electron transport layers for efficient and stable perovskite solar cells made in ambient conditions

“…According to reports, the enhanced initial V OC and slowed decay trend indicate that E-SnO 2 -PSCs have longer carrier lifetimes and lower carrier recombination rates, implying a significant reduction in defect density. 57,58…”

“…According to reports, the enhanced initial V OC and slowed decay trend indicate that E-SnO 2 -PSCs have longer carrier lifetimes and lower carrier recombination rates, implying a significant reduction in defect density. 57,58 Due to the fragility of the perovskite in the atmospheric environment, improving the stability of PSCs is one of the urgent problems. 59 Most studies have focused on improving the quality of the perovskite layers; however, ETLs can also have a great impact on the stability of the PSCs.…”

Active Functional Groups and Adjacent Dual-Interaction Strategies Enable Perovskite Solar Cells to Prosper: Including Unique Morphology and Enhanced Optoelectronic Performance

“…Interestingly, the strong effect of PHA regulated the morphology of perovskite, that is, irregular protrusions appeared on the flat surface of the perovskite film. The protrusions may provide a convenient channel for carrier transport, which is ultimately reflected in the significant enhancement in photocurrent of PSCs . In addition, our group’s published work demonstrates the experience in fabricating devices under uncontrolled air, which can simplify the experimental process and save cost.…”

“…The protrusions may provide a convenient channel for carrier transport, which is ultimately reflected in the significant enhancement in photocurrent of PSCs. 38 In addition, our group's published work demonstrates the experience in fabricating devices under uncontrolled air, which can simplify the experimental process and save cost. With the above advantages, PHA-processed PSCs in the air environment finally show the excellent photoelectric performance of 20.02% with a superior short-circuit photocurrent density of 22.80 mA cm −2 , which overwhelmingly exceeds 22.28 mA cm −2 of PTA-processed PSCs and 21.60 mA cm −2 of pristine PSCs.…”

“…Previous works have demonstrated that the intermediate PbI 2 ·DMSO formed in the perovskite precursor solution enables retarding the rapid reaction between PbI 2 and organic iodides, involving crystal nucleation and perovskite phase growth, which involves adjusting the process of crystal nucleation and perovskite phase growth. − Synchronously, coordination bonds, ionic bonds, and chemical transformations have been proven as valid passivation methods to overcome the harmful effects of traps. Therefore, additive passivation engineering with active functional groups is endemic in the preparation of perovskite, acts on the defects passivation in bulk/surface/interface, and/or the adjustment for structure and energy at the interface, eventually promoting the crystallization and formation of perovskite film. ,− −O, −S, and −N are commonly active groups that can act as electron donors (Lewis bases) to participate in the formation of Lewis acid–base adducts, dedicated to the purpose of passivating perovskites shallow defects. − Based on the donor−π–acceptor (D−π–A) structure of organic molecules, Wu et al controlled the defects passivation effect by influencing the conjugated polymer formed with PbX 2 , in which different D additive molecules provide different electron density distributions . Yang et al verified the function of −NH 2 on −COOH of phenylpropionic acid (as a Lewis base), including the formation of Lewis adducts with trap states caused by dissociated iodine and the final device performance .…”