Low‐Temperature‐Processed Stable Perovskite Solar Cells and Modules: A Comprehensive Review

Abstract

their mixture while the halide anion X is usually equal to I − , Br − , Cl − , or a mixture of them, is rewarded as the most promising materials for the next generation photovoltaics. The record power conversion efficiencies (PCEs) have recently reached an unprecedented values of 25.7% on singlejunction small scale devices and 17.9% for areas over 800 cm 2 , [1] which are now close to that of the crystalline silicon solar cells. The origin of such high performances is attributed to the appealing photo-physical properties, including strong optical absorption, tunable bandgap, long carrier lifetimes, high carrier mobilities, and low mid-gap state densities. [2] Therefore, PSCs offer a promi sing prospect for future commercialization. Regardless of the several advantages, PSCs still need to solve several issues before scaling up at the industrial level.One of the major concerns in the PSC community is the operational stability of the devices. Unlike silicon solar cells, which are stable for over 25 years or more, [3] PSCs still lag behind, showing inferior stabilities. In particular, literature on low-temperature-processed devices demonstrated relatively lower stabilities when compared to the high-temperature ones. [4] However, through this review we show that the stability progress is on par with the high-temperature ones. Usually, the low operational stability of the devices is due to a number of factors, including oxygen, moisture, light, temperature, and electrical bias. To overcome the stability issue, identification of the origins of these instabilities is indispensable. However, various reports present results without providing all the parameters that are essential for understanding and comparing. Incomplete data reporting leads to great difficulty in understanding the multiple instabilities. Thanks to the consensus agreement among the PSC community, a robust stability testing protocol has now been employed. [5] Moreover, a template for reporting stability results has now been provided to ensure reliability and a better understanding of the instabilities. Various stability measurements help in identifying the type of instability existing in the devices. These stability measurements include dark storage studies (ISOS-D), light soaking tests (ISOS-L), outdoor stability studies (ISOS-O), thermal cycling in the dark (ISOS-T), light-humidity-thermal cycling (ISOS-LT), lightdark-cycling (ISOS-LC), intrinsic stability testing (ISOS-I), and electrical bias in the dark (ISOS-V). [5] The impending commercialization of perovskite solar cells (PSCs) is plodding despite the booming power conversion efficiencies and high stabilities. Most high-performance, stable PSCs are often processed partially with hightemperature processes, increasing the cost of production and energy payback time. Low-temperature-processed PSCs are crucial as they cut down the expenses lowering the barriers to industrial use. In addition, low-temperatureprocessed methods have a wide range of applicability in flexible devices and for tandem applicatio...

Scalable processing for realizing 21.7%-efficient all-perovskite tandem solar modules

“…3C and table S3). We expect that laser scribing ( 35 , 36 ), instead of mechanical scribing, for P2 and P3 processings could allow for an even higher GFF and thus higher module efficiency, given that the subcell widths of tandems that are used herein are much larger than those reported in single-junction perovskite solar modules (table S4).…”

Procedure Based on External Quantum Efficiency for Reliable Characterization of Perovskite Solar Cells

“…[4] PSC technologies are now facing stability and upscaling issues to make commercialization feasible. [5,6] Alongside, as PSCs present measurement challenges, there is increasing attention toward defining best practices for measuring and reporting their performance while also working toward standardized protocols. [7][8][9][10][11][12][13] In this context, the role of the external quantum efficiency (EQE) is debated.…”

Azo‐Initiator‐Induced Cascade Defect Passivation for Efficient and Stable Planar Perovskite Solar Cells

“…[ 1 ] It has been recognized that the intriguing optoelectronic properties of perovskites including suitable bandgap, large carrier mobility, and long carrier lifetime are significant factors for achieving such excellent photovoltaic performance. [ 2,3 ] Nevertheless, the polycrystalline perovskite films are generally obtained at a relatively low temperature with rapid nucleation and crystallization processes from the solution. Under this condition, tremendous structural defects such as uncoordinated ions and dangling bonds are inevitably formed at both perovskite surfaces and grain boundaries (GBs).…”