Minimizing the transport loss and degradation of perovskite optoelectronics via grain dimerization technique

Abstract

As a next‐generation photovoltaic device, perovskite solar cell (PSC) is rapidly emerging by its appealing properties. Nevertheless, owing to the degradation which is initiated from the grain boundaries and dangling bonds on the surface, PSC is struggling with not only power conversion efficiency (PCE) but its stability. Herein, dimerization technique using diphenyl(4‐vinylphenyl)phosphine (DVP) is suggested to heal both bulk and interfaces of the perovskite grains. Effective DVP dimerization results in the minimized‐defect perovskite and constructs strong cross‐linking networks inside the grains, enabling improved device performance, reproducibility and stability. Furthermore, hydrophobic species of DVP boost the stability against humidity, which is confirmed by the solar cell dipped in water. As a result, this work obtained PSCs with improved film morphology, reproducibility and stability by DVP dimerization, achieving 21.1% of PCE stable for 1000 h under extreme conditions (AM 1.5G and 60°C, encapsulated).

Double‐Side Passivation of Perovskite Solar Cells for High Performance and Stability

“…PTMAI acts as a bulky passivator, effectively passivating I vacancies. [45][46][47] Despite its bulky nature, this suggests that the bonding length of Pb-I has increased without creating any additional metallic Pb. [47][48][49][50] For a deeper understanding as to how PTMAI influences the perovskite layer, grazing-incidence X-ray diffraction (GIXRD) was utilized.…”

“…[45][46][47] Despite its bulky nature, this suggests that the bonding length of Pb-I has increased without creating any additional metallic Pb. [47][48][49][50] For a deeper understanding as to how PTMAI influences the perovskite layer, grazing-incidence X-ray diffraction (GIXRD) was utilized. It can be inferred that the surface passivation with PTMAI contributes to the formation of 2D perovskite in a direction perpendicular to the plane, which was confirmed by the GIXRD data of the top and double films in Figure 2c.…”

Synthesis of stable iodoplumbate and perovskite for efficient annealing‐free device and long‐term storage

“…The 5% CsPbBr 3 -alloyed FAPbI 3 showed a hexagonal phase dominantly; however, the 10% CsPbBr 3 -alloyed FAPbI 3 clearly formed a trigonal phase without any high-bandgap impurities (hexagonal perovskite and PbI 2 ). On the other hand, 15% CsPbBr 3 -alloyed FAPbI 3 produced a small amount of PbI 2 phase, indicating that the excess CsPbBr 3 is thermodynamically unfavorable in ambient crystallization due to its high crystallization temperature above 300 • C, while FAPbI 3 crystallizes at 150 • C. 72,73 Therefore, excess CsPbBr 3 may retard crystallization at low temperature. However, the Gibbs-phase diagram of the binary phase indicates that the Gibbs energy decreases at certain alloy compositions, and the 10% CsPbBr 3 -alloyed FAPbI 3 could lower the Gibbs energy down to room conditions.…”

“…The formation of grains and films is also related to the surface energy of the bottom film and neighboring materials, and 10% CsPbBr 3alloyed FAPbI 3 well qualified the minimized disruption in grain formation. 73,74 Once 10% CsPbBr 3 -alloyed FAPbI 3 was confirmed as an effective material for solution and film, optoelectronic analysis was further conducted. Therefore, charge extraction behavior was further measured with steady-state photoluminescence (PL) in Figure 5A and time-resolved photoluminescence (TRPL) spectroscopy in Figure S6.…”

Understanding the Trap Characteristics of Perovskite Solar Cells via Drive-Level Capacitance Profiling

“…The organic–inorganic perovskite is promising as an active area material for next-generation solar cells due to its advantages such as high efficiency, low cost, versatility, tunable band gap, and broad absorption. − However, both the synthesis environment and degradation factors (H 2 O, heat, light, etc.) are some of the challenges that are still drawing attention in the development of perovskite solar cells. − Among these issues are electronic trap states, which are a type of defects in the crystal structure that can immobilize electron/hole carriers, resulting in reduced efficiency by decreasing current and voltage output. − Additionally, these defects can provoke device degradation, leading to lower stability and a shorter lifespan. , To mitigate this issue, researchers are exploring ways to decrease the concentration of trap states in the perovskite layer. ,,− …”