Challenges for commercializing perovskite solar cells

151

127

Stability has become the main obstacle for the commercialization of perovskite solar cells (PSCs) despite the impressive power conversion efficiency (PCE). Poor crystallization and ion migration of perovskite are the major origins of its degradation under working condition. Here, high‐performance PSCs incorporated with pyridine‐2‐carboxylic lead salt (PbPyA2) are fabricated. The pyridine and carboxyl groups on PbPyA2 can not only control crystallization but also passivate grain boundaries (GBs), which result in the high‐quality perovskite film with larger grains and fewer defects. In addition, the strong interaction among the hydrophobic PbPyA2 molecules and perovskite GBs acts as barriers to ion migration and component volatilization when exposed to external stresses. Consequently, superior optoelectronic perovskite films with improved thermal and moisture stability are obtained. The resulting device shows a champion efficiency of 19.96% with negligible hysteresis. Furthermore, thermal (90 °C) and moisture (RH 40–60%) stability are improved threefold, maintaining 80% of initial efficiency after aging for 480 h. More importantly, the doped device exhibits extraordinary improvement of operational stability and remains 93% of initial efficiency under maximum power point (MPP) tracking for 540 h.

Section: Introductionmentioning

confidence: 99%

Efficient Passivation with Lead Pyridine‐2‐Carboxylic for High‐Performance and Stable Perovskite Solar Cells

Wan

et al. 2019

151

127

“…[8] As a unique event in the landscape of solar energy harvesting, perovskite solar cells have experienced an increment of their power conversion efficiency by ≈8% (from 13.4% to 23.7%) in the last 5 years. [8] As a unique event in the landscape of solar energy harvesting, perovskite solar cells have experienced an increment of their power conversion efficiency by ≈8% (from 13.4% to 23.7%) in the last 5 years.…”

mentioning

confidence: 99%

Nitrogen Soaking Promotes Lattice Recovery in Polycrystalline Hybrid Perovskites

Alberti

Deretzis

Mannino

et al. 2019

wide dissemination, and high technological throughput. [8] As a unique event in the landscape of solar energy harvesting, perovskite solar cells have experienced an increment of their power conversion efficiency by ≈8% (from 13.4% to 23.7%) in the last 5 years. [9,10] This technology is expected to successfully contribute to the enormous challenge of future power supply from sustainable energy sources. However, the well-known structural instability of hybrid perovskites under working conditions limits a real market uptake of all the related technologies. Solutions to guarantee the durability of products are mandatory and can be numerous, if the problem is addressed from different perspectives.Within the possible approaches to stabilize the perovskite lattice and its behavior under illumination, recent efforts have focused on introducing various treatments, [11,12] molecules, or additives, [13][14][15][16][17][18][19] through different procedures. Nitrogen has been also exploited as inert species [20][21][22][23][24] but its role is still unfocused. The existing (direct or indirect) findings in the literature stimulate the idea of beneficially using N 2 molecules in technological solutions, if their role is persuasively afforded. [25] N 2 molecules are small, safe, and easy to apply.Related to the material stability, we emphasize that the plethora of perovskites produced in different laboratories, with preparation procedures changing from lab to lab and from time to time, ask for treatments that take care and, in a certain extent, reset the starting conditions in a convenient and reproducible manner. This is particularly needed for small grained perovskite layers, on one hand used to implement pinhole-free coverages, but, on the other hand, offering extended lattice discontinuities due to the high surface to volume ratio. In addition to morphology and environment, temperature-related effects are unavoidable during device operation. [24,26] A rationalization of the phenomena needs to embody heating and thermal cycles to preserve the material integrity and/or the structural reversibility versus temperature.In this framework, we argue that nitrogen species have an active role in the stabilization of all the exposed methylammonium lead iodide (MAPbI 3 ) surfaces via their action at grain shells. This conclusion is independent of the particular On the basis of experiment and theory, a general paradigm is drawn that reconsiders N 2 not simply being an inert species but rather an effective healing gas molecule if entering a methylammonium lead iodide (MAPbI 3 ) layer. Nitrogen is soaked into polycrystalline MAPbI 3 via a postdeposition mild thermal treatment under slightly overpressure conditions to promote its diffusion across the whole layer. A significant reduction of radiative recombination and a concurrent increase of light absorption, with a maximum benefit at 80 °C, are observed. Concomitantly, the current of holes drawn from the surfaces with nanometer resolution through a biased tip is raised by a factor of 3 un...

“…[58] They found that TiO 2 compact layers derived from atomic layer deposition (ALD) contain less pinholes than layers obtained by spin coating and spray pyrolysis methods, thus the ALD-based TiO 2 layer functions as a vigorous hole-blocking layer in PSCs as it offers a large shunt resistance which enables a high PCE of 12.56%. 2019, 9,1900248 [41] www.advancedsciencenews.com in the early stages of PSCs research, the growth process of the perovskite film was not well optimized as they are today, as evidenced by the hard-to-get PCE of 12.56% based on ALD-TiO 2 layer with extremely complex and expensive preparation methods at that time. Particularly, Adv.…”

Section: Wwwadvancedsciencenewscommentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12] Most of the high efficient devices utilize mesoporous and/or compact TiO 2 as electron transport layer (ETL), which needs high processing temperatures. [1][2][3][4][5][6][7][8][9][10][11][12] Most of the high efficient devices utilize mesoporous and/or compact TiO 2 as electron transport layer (ETL), which needs high processing temperatures.…”

Section: Introductionmentioning

confidence: 99%

Simple, Robust, and Going More Efficient: Recent Advance on Electron Transport Layer‐Free Perovskite Solar Cells

Huang

2019

Perovskite solar cells (PSCs) have shown great potential for photovoltaic applications with their unprecedented power conversion efficiency advancement. Such devices generally have a complex structure design with high temperature processed TiO2 as the electron transport layer (ETL). Further careful design of device configuration to fully tap the potentials of perovskite materials is expected. Particularly, for the practical application of PSCs, it is crucial to simplify their device structures thus the associated manufacturing process and cost while maintaining their efficiency to be comparable with the conventional devices. But how simple is simple? ETL‐free PSCs promise the simplest structured, thus simple manufacturing processes and low cost large area PSCs in practical applications. They can also help the further exploration of the great potential of perovskite materials and understanding the working principle of PSCs. Within this review, the evolution of the PSC is outlined by discussing the recent advances in the simplification of device configuration and processes for cost effective, highly efficient, and robust PSCs, with a focus on ETL‐free PSCs. Their advancement, key issues, working mechanism, existing problems, and future performance enhancements. This review aims to promote the future development of low cost and robust ETL‐free PSCs toward more efficient power output.