Laser Patterned Flexible 4T Perovskite‐Cu(In,Ga)Se₂ Tandem Mini‐module with Over 18% Efficiency

Abstract

Perovskite‐Cu(In,Ga)Se2 (CIGS) thin‐film tandem technology provides an exciting prospect to achieve low‐cost high‐efficiency photovoltaic devices by high throughput roll‐to‐roll processing on flexible substrates. However, no report on flexible perovskite‐CIGS mini‐modules has been published due to scribing‐related challenges in realizing near‐infrared (NIR)‐transparent perovskite mini‐modules on flexible substrates. Herein, an NIR‐transparent flexible perovskite mini‐module with an efficiency of 10.8% and an NIR‐transparency of over 75% is reported. All‐laser scribed interconnection approach is used to realize monolithic interconnection of mini‐modules on thermally sensitive soft flexible substrate. An analytical method is utilized to optimize the mini‐module layout and achieve a geometric fill factor of over 93%. Further, as a proof of concept, a flexible perovskite‐CIGS tandem mini‐module with an efficiency of 18.4% on an aperture area of 2.03 cm2 is demonstrated. To conclude, pathways for improving the efficiency of flexible NIR‐transparent perovskite mini‐modules are discussed.

Rapid 2D Patterning of High‐Performance Perovskites Using Large Area Flexography

“…[26] This additional scribing step, however, is not ideal given that it introduces additional fabrication costs, increasing CapEx, and causes damage to underlying layers. Laser patterning is also limited in resolution by the heat affected zone that extends beyond the laser spot, [27] introducing residual debris comprised of ablated material that increases dead area and reduces modules' aperture efficiency [28] and can serve as accelerated degradation sites for PbI 2 . Consequently, there remains a need for large-area fabrication processes that integrate additive patterning, which would reduce production costs by eliminating the need for expensive scribing steps and would enable more complex pattern formation with multiple perovskite compositions that is currently impossible with the combination of blanket deposition and subtractive methods.…”

The issues on the commercialization of perovskite solar cells

“…In addition, the flexible two-terminal (2T) perovskite/perovskite tandem solar cells [254] and 4T perovskite-Cu(In,Ga)Se 2 tandem mini-module [255] have also been developed in 2022. Tan et al enhanced the contact between NiO and perovskite through inserting a self-assembled monolayer.…”

Functional Layers of Inverted Flexible Perovskite Solar Cells and Effective Technologies for Device Commercialization

“…[42] A higher efficiency can be achieved by stacking perovskites with traditional photovoltaic materials (silicon or CIGS), or stacking two perovskites with complementary band gaps to expand the light absorption spectrum. [44,47] Among tandem solar cells, multijunction all-PSCs combine low thermalization losses in multijunction structures with the favorable properties of perovskites, and thus possess the advantages of compatibility with flexible substrates, low cost, and mass fabrication. For all-perovskite tandem solar cells, Pb-Sn mixed perovskites with a narrow bandgap are usually required, which limits the utilization of metal oxide charge transport materials due to the induced oxidation of Sn 2þ .…”

“…Thus, in recent years, researchers' research interests focus on high-performance flexible solar cells. [41][42][43][44][45][46][47] It must be pointed out that the perovskites are more advantageous in fabrication of various flexible devices due to their low-temperature processability and high flexibility comparing with other solar cell materials. [48,49] More specifically, while other flexible solar cells, such as dyesensitized solar cells (DSSCs), cadmium telluride solar cells (CdTe), copper indium gallium selenide solar cells (CIGS), and organic photovoltaic solar cells (OPV), exhibit low PCEs, high cost, complicated fabrication process, and insufficient flexibility, [50][51][52] flexible perovskite solar cells (FPSCs) possess advantages of high PCEs, low cost, simple fabrication process, and sufficient flexibility.…”

“…[41][42][43][44][45][73][74][75][76] More importantly, compared with their regular counterparts, inverted FPSCs are more suitable for the preparation of tandem solar cells to improve PCEs of FPSCs to accelerate commercialization. [47,[77][78][79] Therefore, inverted FPSCs with excellent optoelectronic properties have triggered intense research interests from scientists especially in recent years. The efficiency of single-junction inverted FPSCs has been improved from 6.4% in 2013 to 21.76% in 2022 (Figure 1), and the PCE of tandem inverted FPSCs has even reached 24.7%, indicating their promising commercialization prospects.…”