A transparent, solvent-free laminated top electrode for perovskite solar cells

Abstract

A simple lamination process of the top electrode for perovskite solar cells is demonstrated. The laminate electrode consists of a transparent and conductive plastic/metal mesh substrate, coated with an adhesive mixture of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS, and sorbitol. The laminate electrode showed a high degree of transparency of 85%. Best cell performance was achieved for laminate electrodes prepared with a sorbitol concentration of ~30 wt% per milliliter PEDOT:PSS dispersion, and using a pre-annealing temperature of 120°C for 10 min before lamination. Thereby, perovskite solar cells with stabilized power conversion efficiencies of (7.6 ± 1.0)% were obtained which corresponds to 80% of the reference devices with reflective opaque gold electrodes.

Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

“…Some groups have instead used lamination processes for applying the top electrode which may be useful for producing either transparent cells or cells on metal foils with efficiencies of 7.6%-13.3%; 89,90 however, currently laminated solar cells evidenced bigger hysteresis than the Au-electrode based analogues and the application over large area modules where patterning is necessary must still be investigated.…”

Metal‐Nanowire‐Electrode‐Based Perovskite Solar Cells: Challenging Issues and New Opportunities

“…Furthermore, because the fabrication steps of MeNW-networks and the bottom parts of PSCs are separated, each compartment can be optimized without chemical/physical interactions between them; thus, the problems induced from mismatched features between OMHP and MeNW-networks can be alleviated by this approach. [118] Two external force sources, ball-bearing transfer, [116,117,162] and roll-lamination, [118,119,[156][157][158] have been introduced in previous reports on PSCs using mechanically deposited MeNW-networks (Figure 13d,e). Moon's group reported PSCs using mechanically transferred CuNW-network electrodes as a top electrode.…”

“…[162] In addition to the ball-bearing method, a roll-lamination method has been employed for the mechanical integration of MeNW-network electrodes (Figure 13e). [118,119,[156][157][158] Unlike the case of the ball-bearing transfer method, it can uniformly press the entire cell surface and afford faster integration at a programmed rate. However, a very thick transparent conductive adhesive (TCA) layer with a thickness of at least a few micrometers is indispensably necessary for this method (Figure 13f), [158] and the electronic/optical properties of the TCA layer can critically affect cell performance.…”

“…As example cases, a grid-type network of Ni wires, with a width of ≈10 µm, was successfully exploited as a transparent conductive electrode of PSCs, [119,[156][157][158] suggesting the feasible application of Ni nanowires to PSCs. Although the stability issue with these one-dimensional Ni materials in PSCs has not yet been fully addressed, the NiNWs are believed to possess a fundamental potential as an appropriate alternative for electrodes in PSCs.…”

“…[92,161] Furthermore, so as to avoid direct contact of polar solvents, mechanical stacking of preformed MeNW-networks has been exploited as an alternative way of fabricating top MeNWnetwork electrodes in PSCs. [116,117,119,[156][157][158] Briefly, a MeNWs network is separately fabricated on another substrate, while the bottom part of PSCs containing the OMHP layer is fabricated on glass substrates using routine methodologies. Then, the MeNW-networks are combined with the bottom part by an external mechanical force.…”