Recent Progress Toward Commercialization of Flexible Perovskite Solar Cells: From Materials and Structures to Mechanical Stabilities

Abstract

Solar photovoltaic (PV) energy is taking an increasingly important role all over the world. Among different solar cells, perovskite solar cells (PSCs) are regarded as the next-generation technology that could further decrease the manufacturing cost with comparable efficiency to silicon solar cells. Perovskite materials possess marvelous optoelectronic properties like high light absorption coefficient, tunable bandgap, and long charge diffusion length. [1][2][3][4][5][6][7][8] Recently, state-of-the-art devices have achieved tremendous progress with power conversion efficiencies (PCEs) exceeding 25%. [9][10][11] Besides, with the intrinsic mechanical flexibility and low-temperature processability, PSCs are able to be prepared on flexible substrates, which will broaden the application areas in portable electronics, wearable devices, and so on. [12][13][14][15][16][17] Moreover, PSCs could be fabricated by the roll-to-roll printing process, which has already been successfully demonstrated in the commercialization of organic PVs. Needless to say, flexible perovskite solar cells (FPSCs) have become a significant topic in practical applications of PSCs (See Figure 1). [18] Kumar et al. reported the first FPSC in 2013, and the PCE was only 2.62%. [19] In this work, polyethylene terephthalate (PET) was used as a flexible substrate, followed by low-temperature deposited ZnO nanorods. Currently, the record PCE of flexible devices is still lower than that of rigid ones. To some extent, the loss is inevitably caused by the trade-off between the requirement of mechanical flexibility for application and mechanical rigidity for fabrication. Different from rigid PSCs, the morphologies of the layers in FPSCs are difficult to control

Uniform Coverage Functional Layers Enable High‐Efficient Flexible Perovskite Solar Modules with an Outstanding Fill Factor

“…[1][2][3] And the low-temperature process makes it suitable for flexible modules on polymer substrates, such as polyethylene glycol terephthalate (PET) and polyethylene naphthalate (PEN). [4][5][6][7] Currently, a record PCE of 23.35% has been achieved on PEN/indium tin oxide (ITO) flexible substrates with inverted structure. [8] However, the most outstanding PCEs were obtained in relatively small areas (<0.1 cm 2 ) with antisolvent, [9,10] and few works have reported high-efficient flexible perovskite solar modules (FPSMs), with their fill factor (FF < 70%) still lagging behind those of rigid devices (%80%).…”

Unveiling the Fatigue Behavior of 2D Hybrid Organic–Inorganic Perovskites: Insights for Long‐Term Durability

“…[8] The relative softness of the lattice owing to the hybrid organicinorganic nature, [9] along with the great semiconductor performance, allows HOIPs to be incorporated into flexible and wearable electronics to greatly promote the advances in the Internet of Things. [10][11][12] 2D HOIPs can be structurally derived from their 3D counterparts, [2,13] which further improve the materials' chemical stability [13] and mechanical resilience, [9,[14][15][16][17] and offer more tunability in the structure and chemistry for material properties engineering to meet various device application needs. [9,13] Mechanical strain is universally found in HOIP-based devices.…”

“…[20,23,24] As a result, the structure-property relationship of HOIPs (both in 3D and 2D forms) regarding their elastic and fracture properties have been widely explored over the past few years, [9] where the materials are typically loaded under quasi-static conditions and simultaneous mechanical responses are recorded. However, in practical applications, HOIPs are more commonly found under subcritical (below the fracture strength, e.g., during strain engineering) [23,24] and cyclic loadings (e.g., during repeated bending in flexible electronics applications [10][11][12] or thermal strain arising from temperature fluctuations). [21] Materials typically suffer from mechanical fatigue under such loading conditions [25] over the long service life of the device (ideally 10 to 20 years), [26] and it is imperative to understand this behavior to evaluate the long-term mechanical reliability.…”

Performance Enhancement of Flexible Perovskite Solar Cells Enabled by Ammonium Halide Passivation

“…Since the first report of organic–inorganic hybrid perovskite solar cells (PSCs) in 2009, they have become a focal point in the research of renewable energy sources, and their power conversion efficiency (PCE) has rapidly increased from 3.8 to 26.1% . Basically, the PSCs have advantages of a high PCE, low cost, , a simple preparation process, excellent flexibility, and low-temperature preparation . These merits ensure the feasibility of making flexible PSCs (f-PSCs).…”

“…2 Basically, the PSCs have advantages of a high PCE, 3 low cost, 4,5 a simple preparation process, 6 excellent flexibility, 7 and low-temperature preparation. 8 These merits ensure the feasibility of making flexible PSCs (f-PSCs). At present, the highest PCE of f-PSCs is 23.84%, and f-PSCs can be achieved by the two-step sequential deposition method.…”