Flexible Perovskite Solar Cells: From Materials and Device Architectures to Applications

Abstract

Perovskite solar cells (PSCs) are being rapidly developed at a fiery stage due to their marvelous and fast-growing power conversion efficiency (PCE). Advantages such as high PCE, solution processability, tunable band gaps, and flexibility make PSCs one of the research hot spots in the energy field. Flexible PSCs (f-PSCs) owing to high power-to-weight ratios can be promising candidates to serve as power sources in mobile energy systems, space energy systems, portable functional devices, and so on. Herein, we give a review on recent progress in f-PSCs involving flexible substrates and flexible transparent electrodes, performance enhancement by optimizing functional layers, large-scale fabrication techniques, flexibility promotion strategies, and their potential applications. Furthermore, perspectives are discussed on the future development of f-PSCs.

Dual‐Interface‐Reinforced Flexible Perovskite Solar Cells for Enhanced Performance and Mechanical Reliability

“…[ 8 ] Note that other approaches, such as grain‐boundary modification by a fullerene network, [ 29 ] have been used to strengthen the MHP thin film. [ 7 ] Second, it also toughens the 3D‐MHP/HTL interface (2–3), where the G C has increased by ≈75%, to 0.82 J m −2 (w/LD; Figure 2b). The net result is even slower loss of the PV performance in the SAM+LD case (Figure 5a–d).…”

“…[8] Progress is being made in f-PSCs, but their power-conversion efficiency (PCE) and operational stability still lag behind their rigid counterparts deposited on glass substrates. [3][4][5][6][7] The highest PCE reported in f-PSCs thus far is 22.44%, [9] and the longest operational stability under 1-sun continuous illumination with maximum power point (MPP) tracking (unencapsulated, N 2 atmosphere, and 45 °C) is T 90 of 800 h (90% of initial PCE retained) reported by us recently. [8] Furthermore, mechanical reliability is a major concern in f-PSCs.…”

“…This is because the externally applied mechanical stresses during manufacturing and service (bending, stretching, and/or twisting) in f-PSCs are expected to be much more severe, which can result in the fracture of the brittle 3D metal-halide perovskite (MHP) thin film itself and/or its interfaces with the electron-transport layer (ETL) and the hole-transport layer (HTL) on either side. [7,8,10] Several approaches have been used to mitigate these effects in f-PSCs, and are summarized in a recent review. [7] Typically, cyclic bending tests are performed to evaluate the mechanical durability of f-PSCs.…”

Ionogel-perovskite matrix enabling highly efficient and stable flexible solar cells towards fully-R2R fabrication

“…Thus, it is urgent to develop novel elastic dopants with high elongation as well as preferred easy self-healing ability without sacrificing carrier mobility or the original advantages in the above strategies, which would be highly important towards efficient and stable flexible PSCs. 29,30…”

“…Thus, it is urgent to develop novel elastic dopants with high elongation as well as preferred easy self-healing ability without sacrificing carrier mobility or the original advantages in the above strategies, which would be highly important towards efficient and stable flexible PSCs. 29,30 In this work, a multi-functional ionogel (IG) was designed by the incorporation of small-molecule ionic liquids into a crosslinkable polymer network, which can be incorporated in situ in R2R-compatible bar-coated perovskite films. Engineering of the ionic liquids and functional groups in the polymer network can effectively regulate both the mechanical properties and passivation effect of the perovskite films and devices.…”