Carbon-Based Electrode Engineering Boosts the Efficiency of All Low-Temperature-Processed Perovskite Solar Cells

Abstract

Carbon electrode-based perovskite solar cells (PSCs) with low-cost and long-term stability have been recognized as a competitive candidate toward future practical applications. However, energy level mismatch and ineffective hole extraction at the carbon electrode/perovskite interface limit device performance. Herein, we develop a low-cost carbon-based electrode that utilizes a cheap small-molecule semiconductor copper phthalocyanine (CuPc) as both the interface modifier and dopant. The resultant planar PSC yields a power conversion efficiency of 14.8%, ∼30% higher than that based on the bare carbon electrode. This is due to higher work function and better hole extraction properties of the CuPc-modified carbon electrodes. The simple modification process of the carbon electrode has potential applications for large-scale fabrication. We further applied such electrodes in large-area solar modules and flexible solar cells, demonstrating their capability of upscaling and flexibility.

Perovskite‐Compatible Carbon Electrode Improving the Efficiency and Stability of CsPbI2Br Solar Cells

“…[ 22 ] P‐type copper phthalocyanine (CuPc) has the advantages of thermal stability and high hole mobility. [ 23 ] In this work, CuPc HTL was used to further improve the PCE of related PSCs. Figure 4b shows a cross‐sectional scanning electron microscope (SEM) image of PCCE‐based PSCs with the structure of FTO/TiO 2 /CsPbI 2 Br/CuPc/PCCE, where the thicknesses of compact TiO 2 layer and CsPbI 2 Br layer are about 50 and 500 nm, respectively.…”

Recent Progress of All‐Bromide Inorganic Perovskite Solar Cells

“…At present, there are no studies on large‐scale solar module level using CsPbBr 3 perovskite, and the majority of the reported CsPbBr 3 PCEs (Table ) were obtained only on relatively small active areas (<1 cm 2 ) . As comparison, substantial progress has been made in the fabrication of large‐area OIH‐PSCs, and it is becoming a standard to demonstrate PSCs and modules with total areas larger than 10 cm 2 . Therefore, keeping in mind commercialization, more efforts are needed in the development of fabrication processes aiming at large‐area CsPbBr 3 PSCs with high PCE, high‐throughput, and minimum batch‐to‐batch variations.…”

Low-temperature carbon-based electrodes in perovskite solar cells

“…In the cells where the hole-selective layer is present it can be added either as a dense film between the perovskite and carbon (before electrode deposition) or it can be added directly to the LTCB-paste prior to the paste manufacturing process. 138 In the latter case, the HSL is formed directly at the perovskite/carbon interface upon the curing process of the electrode.…”

“…The module retained 75% of its initial PCE of 6% after 2000 bending cycles. 138 One of the key problems of flexible PSCs is the use of expensive conductive metal oxides, such as ITO, which significantly hinders the full commercialization potential. In other thin-film technologies, the front-contact materials such as Al-doped zinc oxide (AZO) and thin transparent Ag are not chemically compatible with perovskite in the long-term.…”