Search

Methylammonium chloride (MACl) additive is almost irreplaceable in high‐performance formamidine perovskite photovoltaics. Nevertheless, Some of the problems that can arise from adding MACl are rarely mentioned. Herein, it is proposed for the first time that the addition of MACl would cause the non‐stoichiometric ratio in the perovskite film, resulting in the halogen vacancy. It is demonstrated that the non‐synchronous volatilization of methylamine cations and chloride ions leads to the formation of halogen vacancy defects. To solve this problem, the NH4HCOO is introduced into the perovskite precursor solution to passivate the halogen vacancy. The HCOO− ions have a strong force with lead ions and can fill the halogen vacancy defects. Consequently, the champion devices' power conversion efficiency (PCE) can be improved from 21.23% to 23.72% with negligible hysteresis. And the unencapsulated device can still retain >90% of the initial PCE even operating in N2 atmosphere for over 1200 h. This work illustrates another halogen defect source in the MACl‐assisted formamidine perovskite photovoltaics and provides a new route to obtain high‐performance perovskite solar cells. [ABSTRACT FROM AUTHOR]

The remarkable optoelectronic properties of organometal halide perovskite solar cells have captivated significant attention in the energy sector. Nevertheless, the instability of 3D perovskites, despite their extensive study and attainment of high-power conversion efficiency, remains a substantial obstacle in advancing PSCs for practical applications and eventual commercialization. To tackle this issue, researchers have devised mixed-dimensional perovskite structures combining 1D and 3D components. This innovative approach entails incorporating stable 1D perovskites into 3D perovskite matrices, yielding a significant improvement in long-term stability against various challenges, including moisture, continuous illumination, and thermal stress. Notably, the incorporation of 1D perovskite yields a multitude of advantages. Firstly, it efficiently passivates defects, thereby improving the overall device quality. Secondly, it retards ion migration, a pivotal factor in degradation, thus further bolstering stability. Lastly, the inclusion of 1D perovskite facilitates charge transport, ultimately resulting in an elevated device efficiency. In this succinct review, we thoroughly encapsulate the recent progress in PSCs utilizing 1D/3D mixed-dimensional architectures. These advancements encompass both stacked bilayer configurations of 1D/3D structures and mixed monolayer structures of 1D/3D. Additionally, we tackle critical challenges that must be surmounted and offer insights into the prospects for further advancements in this domain. [ABSTRACT FROM AUTHOR]

• DPEBF 4 can effectively reduce the volume defects of perovskite film and improve the film crystallinity. • DPEBF 4 modification results in that SnO 2 ETL matches perovskite energy level better and promotes electron transfer. • DPEBF 4 as interfacial modification layer enhance the PCE and long-term stability of PSCs. SnO 2 as an electron transport layer (ETL) has recently been used for perovskite solar cells (PSCs) due to high transmittance and electron mobility. However, the mismatched band energy alignment of ETL and perovskite layer result in serious nonradiative recombination limiting the improvement of PSCs performance. Here, 2-(Diphenylphosphino)ethanaminium tetrafluoroborate (DPEBF 4) as buried interface was introduced between ETL and perovskite. The [BF 4 ]− anion in DPEBF 4 can interact with SnO 2 to reduce the surface defect of SnO 2. While [DPE]+ cation is more inclined to interact with Pb2+ and I−, the terminal strong interaction will promote crystallization of perovskite film quality and passivate buried surface defects. As a result, device performance was significantly improved by introducing DPEBF 4 layer, the power conversion efficiency (PCE) increase from 20.50 % for control devices to 23.84 %. The work provides an interfacial double-tonic strategy for ETL and perovskite crystals to achieve high-performance perovskite photovoltaic devices. [ABSTRACT FROM AUTHOR]

Despite the successful improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSCs), the issue of instability is still a serious challenge for their commercial application. The issue of the PSCs mainly originates from the decomposition of the organic-inorganic hybrid perovskite materials, which will degrade upon humidity and suffer from the thermal environment. In addition, the charge transport layers also influence the stability of the whole devices. In this study, inorganic transport layers are utilized in an inverted structure of PSCs employing CsPbIBr 2 as light absorbent layer, in which nickel oxide (NiO x ) and cerium oxide (CeO x ) films are applied as the hole transport layer (HTL) and the electron transport layer (ETL), respectively. The inorganic transport layers are expected to protect the CsPbIBr 2 film from the contact of moisture and react with the metal electrode, thus preventing degradation. The PSC with all inorganic components, inorganic perovskite and inorganic transport layers demonstrates an initial PCE of 5.60% and retains 5.56% after 600 s in ambient air at maximum power point tracking.