Abstract
Perovskite solar cells (PSCs) have attracted much attention due to their low-cost fabrication and high power conversion efficiency (PCE). However, the long-term stability issues of PSCs ...remain a significant bottleneck impeding their commercialization. Inverted PSCs with a p-i-n architecture are being actively researched due to their concurrent good stability and decent efficiency. In particular, the PCE of inverted PSCs has improved significantly in recent years and is now almost approaching that of n-i-p PSCs. This review summarizes recent progress in the development of high-efficiency inverted PSCs, including the development of perovskite compositions, fabrication methods, and counter electrode materials (CEMs). Notably, we highlight the development of charge transport materials (CTMs) and the effects of defect passivation strategies on the performance of inverted PSCs. Finally, we discuss the remaining issues and perspectives of high-efficiency inverted PSCs.
The coordination effects of additives during perovskite crystal growth are investigated, and a novel technique to fabricate high‐quality perovskite thin films by introduction of weak coordination ...additives (e.g., acetonitrile) in the precursors is demonstrated.
Perovskite solar cells (PSCs) have attracted great attention in the past few years due to their rapid increase in efficiency and low‐cost fabrication. However, instability against thermal stress and ...humidity is a big issue hindering their commercialization and practical applications. Here, by combining thermally stable formamidinium–cesium‐based perovskite and a moisture‐resistant carbon electrode, successful fabrication of stable PSCs is reported, which maintain on average 77% of the initial value after being aged for 192 h under conditions of 85 °C and 85% relative humidity (the “double 85” aging condition) without encapsulation. However, the mismatch of energy levels at the interface between the perovskite and the carbon electrode limits charge collection and leads to poor device performance. To address this issue, a thin‐layer of poly(ethylene oxide) (PEO) is introduced to achieve improved interfacial energy level alignment, which is verified by ultraviolet photoemission spectroscopy measurements. Indeed as a result, power conversion efficiency increases from 12.2% to 14.9% after suitable energy level modification by intentionally introducing a thin layer of PEO at the perovskite/carbon interface.
A thin layer of polyethylene oxide (PEO) is introduced to modify the energy level alignment at the interface between an FA0.8Cs0.2PbI2.64Br0.36 perovskite and a carbon electrode. The PEO‐modified perovskite cell shows 22% increase in power conversion efficiency and enhanced stability keeping 77% of the initial value after being aged for 192 h under the conditions of 85 °C and 85% humidity without encapsulation.
Besides high efficiency, the stability and reproducibility of perovskite solar cells (PSCs) are also key for their commercialization. Herein, we report a simple perovskite formation method to ...fabricate perovskite films with thickness over 1 μm in ambient condition on the basis of the fast gas-solid reaction of chlorine-incorporated hydrogen lead triiodide and methylamine gas. The resultant thick and smooth chlorine-incorporated perovskite films exhibit full coverage, improved crystallinity, low surface roughness and low thickness variation. The resultant PSCs achieve an average power conversion efficiency of 19.1 ± 0.4% with good reproducibility. Meanwhile, this method enables an active area efficiency of 15.3% for 5 cm × 5 cm solar modules. The un-encapsulated PSCs exhibit an excellent T
lifetime exceeding 1600 h under continuous operation conditions in dry nitrogen environment.
The booming growth of organic-inorganic hybrid lead halide perovskite solar cells have made this promising photovoltaic technology to leap towards commercialization. One of the most important issues ...for the evolution from research to practical application of this technology is to achieve high-throughput manufacturing of large-scale perovskite solar modules. In particular, realization of scalable fabrication of large-area perovskite films is one of the essential steps. During the past ten years, a great number of approaches have been developed to deposit high quality perovskite films, to which additives are introduced during the fabrication process of perovskite layers in terms of the perovskite grain growth control, defect reduction, stability enhancement, etc. Herein, we first review the recent progress on additives during the fabrication of large area perovskite films for large scale perovskite solar cells and modules. We then focus on a comprehensive and in-depth understanding of the roles of additives for perovskite grain growth control, defects reduction, and stability enhancement. Further advancement of the scalable fabrication of high-quality perovskite films and solar cells using additives to further develop large area, stable perovskite solar cells are discussed.
This review summarizes recent progress on additive strategies employed for fabrication of large-scale perovskite solar cells and modules. Additives promote perovskite grain growth, defects reduction, and stability enhancement in addition to power-conversion-efficiency. Display omitted
Organic light emitting diodes (OLEDs) employing organic thin‐film based emitters have attracted tremendous attention due to their widespread applications in lighting and as displays in mobile devices ...and televisions. The novel thin‐film photovoltaic techniques using organic or organic–inorganic hybrid materials such as organic photovoltaics (OPVs) and perovskite solar cells (PSCs) have become emerging competitive candidates with regard to the traditional photovoltaic techniques on account of high‐efficiency, low‐cost, and simple manufacturing processing properties. However, OLEDs, OPVs, and PSCs are vulnerable to the undesired degradation induced by moisture and oxygen. To afford long‐term stability, a robust encapsulation technique by employing materials and structures that possess high barrier performance against oxygen and moisture must be explored and employed to protect these devices. Herein, the recent progress on specific encapsulation materials and techniques for three types of devices on the basis of fundamental understanding of device stability is reviewed. First, their degradation mechanisms, as well as, influencing factors are discussed. Then, the encapsulation technologies and materials are classified and discussed. Moreover, the advantages and disadvantages of various encapsulation technologies and materials coupled with their encapsulation applications in different devices are compared. Finally, the ongoing challenges and future perspectives of encapsulation frontier are provided.
Thin‐film, cover, and hybrid encapsulation technologies, that function as a moisture and oxygen permeation barrier and mechanical protection to prevent leakage of toxic by‐product, and limit decomposition of reactants in a confined space, can be applied in organic light emitting diodes, organic and perovskite solar cells, leading to robust stability and long lifetime in three types of devices.
Minimization of defects in absorber materials is essential for hybrid perovskite solar cells, especially when constructing thick polycrystalline layers in a planar configuration. Here, a simple ...methylamine solution‐based additive is reported to improve film quality with nearly an order of magnitude reduction in intrinsic defect concentration. In the resultant film, an increase in carrier lifetime as a result of a decrease in shallow electronic disorder is observed. This superior crystalline film quality is further evidenced via a doubled spin relaxation time as compared with other reports. Bearing sufficient carrier diffusion length, a thick absorber layer (≈650 nm) is implemented in planar devices to achieve a champion power conversion efficiency of 20.02% with a stabilized output efficiency of 19.01% under one sun illumination. This work demonstrates a simple approach to improve hybrid perovskite film quality by substantial reduction of intrinsic defects for wide applications in optoelectronics.
A simple methylamine solution‐based additive to improve film quality with nearly an order of magnitude reduction in the concentration of intrinsic defects is reported, and the relevant perovskite solar cells achieve a champion power conversion efficiency of 20.02% with a stabilized output efficiency of 19.01% under 1 sun illumination.
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