Search

4-terminal tandem technology is a straightforward approach to bring to the market perovskite/crystalline silicon tandem modules. However, dealing with 4 terminals poses a challenge at system level for practical deployment. We have produced large area 4-terminal perovskite/crystalline silicon tandem modules for a study of the performance of a 2-terminal voltage matched (2T VM) configuration versus an unconstrained 4-terminal (4T) configuration. The 2T VM configuration is a very interesting proposition to deal in practice with 4 terminal tandem technology at module level. The tandem module assembly consisted of 3 perovskite submodules of 31 cells and 100 cm2 aperture area each, and 3 c-Si submodules of 16 cells and 100 cm2 aperture area each. We have varied the voltage-mismatch from 13% to 42%, by varying the electrically connected c-Si string length. The resulting power loss for 2T VM relative to 4T varied between 4.5% and 20%. We have focused on combining one perovskite submodule with the series connection of the three silicon submodules, using the other two perovskite submodules as optical filter only. We find that the 2T VM power output follows roughly the expected values calculated from the individual characteristics, however, with a 2-3% additional power loss. Analysis of this additional power loss will require precise monitoring of time dependence of I-V characteristics, transmission of the submodules, and other relevant parameters.

Scalable sheet-to-sheet slot die coating processes have been demonstrated for perovskite solar cells and modules. The processes have been developed on 6 in. × 6 in. glass/ITO substrates for two functional layers: the perovskite photo-active layer and the Spiro-OMeTAD hole transport layer. Perovskite solar cells produced using these slot die coating processes demonstrate device performances identical to the spin coated devices. All manufactured devices illustrate a high level of reproducibility. The developed slot die coating processes were also used for the manufacturing of perovskite PV modules. Large area modules of 12.5 × 13.5 cm2 were realized by slot die coating on 6 in. × 6 in. substrates in combination with newly developed laser ablation processes for conventional P1-P2-P3 monolithic cell interconnections. The modules demonstrate power conversion efficiencies above 10%, with a power output of 1.7 W. This achievement is an important milestone in the development of up-scalable manufacturing technologies for perovskite PV modules.

This paper reports on the analysis and comparison of mechanical and laser patterning in the fabrication of perovskite thin-film photovoltaic modules. Besides stability, device upscaling and module fabrication is a key challenge for the commercialization of perovskite photovoltaics. Here, the focus is on the optimization of the P2 interconnection that represents the electrical connection between serially connected cells in a module. The specific contact resistivity for P2 interconnection is determined by using an enhanced transmission line method. Mechanical or laser patterning are used to fabricate 4 cm $^{2}$ modules with aperture area efficiencies of up to 15.3% and geometrical fill factors as high as 94%. With the application of a simulation program with an integrated circuit emphasis-based electrical device model, the interconnection losses are quantified, and optimal designs for perovskite modules are presented.

In order to commercialize the perovskite solar cells (PSC) technology, efficient and industrial deposition methods over large areas have to be adopted, and the device architectures have to provide long term stability. In this work we combine several upscalable deposition methods to develop a stable semitransparent PSC. The control of the uniformity of perovskite crystallization by tailoring the ink formulation and the drying process was pursued in order to drastically reduce the efficiency losses over an area increase of 3 orders of magnitude (from 0.04 to 100 cm2). When adopting sputtered ITO as top electrode, the stack retains up to 90% of the initial performance after 1000hrs at 85 °C. The use of laser patterning to define P1 P2 and P3 scribes for series interconnected modules enables the fabrication of thermally stable minimodule (4cm2) and large module (100cm2). Finally an outlook on the use of the perovskite device as top cell in a 4T tandem architecture with commercial c-Si cells will be provided.

In this work, efficient rigid and flexible semi-transparent perovskite solar cells (ST-PSCs) were prepared in inverted (light incidence through hole transport layer) configuration. All layers were deposited by a combination of low-temperature solution-based, sputtering and spatial atomic layer deposition (sALD) techniques, which can be potentially up-scalable for sheet to sheet and roll to roll manufacturing lines. The rigid and flexible opaque PSCs reach stabilized power conversion efficiency (PCE) of 19% and 16% [1], while rigid ST-PSC reaches 16.4% stabilized PCE. Besides those results, we have developed our current flexible opaque stack to the flexible semi-transparent stack using top TCO electrode and sALD buffer layer. We also highlight that the inverted configuration exhibited extremely high infrared transparency [2] and a remarkable stability during the light and thermal stress. The encapsulated ST-PSCs retained 93% of their initial stabilized PCE after 3000h aging at 85°C in a nitrogen atmosphere. Interestingly, using highly transparent transport layers, rigid and flexible ST-PSCs show comparable efficiency by illumination from both rear and front TCO sides, resulting in a bifacility of 99%.

The industrialization of perovskite solar cells (PSC) require processes to efficiently deposit the constituent layers over large areas. In this work we optimized the use of slot die coating process for both sheet-to-sheet (S2S) and roll-to-roll (R2R) manufacturing. Particular focus have been put on the control of the uniformity of perovskite crystallization by tailoring the ink formulation and the drying process in order to avoid any efficiency losses over an area increase of 3 orders of magnitude (from 0.09 to 144 cm2). In this way we were able to fabricate 144 cm2 modules with 13.8% stabilized efficiency on aperture area on glass (14.5% on active area). At the same time, by developing the R2R slot die deposition process of the perovskite layer, we demonstrated 160 cm2 flexible module with 10.1 % stabilized efficiency on aperture area (11.0% on active area). In addition, fully R2R coated cells exhibit up to 16% efficiency. An outlook on how to upscale more stable perovskite cells (i.e. with pin structure) will be given. These results prove how to optimize the upscaling process towards large area manufacturing of perovskite solar modules on both rigid and flexible substrate.

© 2018 The Royal Society of Chemistry. Thin film perovskite photovoltaic devices combine high power conversion efficiencies with low weight, large area, high speed production capabilities and high versatility in form factor. With this paper, an additional feature is added to the device property portfolio: optical transparency. Results on translucent perovskite modules with selectively tuned levels of transparency are reported by applying the industrially established fabrication process of partial area ablation to high efficiency opaque devices. After process completion, the final devices consist of opaque areas that absorb the light, and transparent areas that permit neutral light transmission. We compare the effectiveness of using two active area removal techniques: mechanical scribing and laser ablation, and determine the factors that limit the maximum transparency and power conversion efficiency. Moreover, we show how the choice of the ablation method and design of the active area removal pattern affect and limit the maximum light utilization efficiency ratio that can be achieved with this fabrication process. The resulting 4 cm2 translucent modules cover a range of visible light transparency from 7 to 37% with a corresponding power conversion efficiency of 5 to 13%. ispartof: JOURNAL OF MATERIALS CHEMISTRY C vol:6 issue:12 pages:3034-3041 status: published

Organometallic halide perovskite solar cells (PSCs) are extremely promising novel materials for thin-film photovoltaics, exhibiting efficiencies over 22% on glass and over 17% on foil 1, 2. First, a sheet-to-sheet (S2S) production of PSCs and modules on 152x152 mm2 substrates was established, using a combination of sputtering, e-beam evaporation, slot die coating and thermal evaporation (average PCE of 14.6 ± 1.3 % over 64 devices, more than 10% initial PCE on modules). Later the steps towards a roll-to-roll production will be investigated, starting from the optimization of the stack to make it compatible with a faster production at low temperature. A water based SnOx nanoparticles dispersion was used as solution processable ETL, and the deposition process was scaled-up from spin coating to R2R slot die coating on a 300 mm wide roll of PET/ITO. R2R production is often carried out in ambient atmosphere and involve the use of large volumes of materials, thus a first point is the development of a green solvent and precursor system for the perovskite layer to prevent the emission of toxic compound in the environment. The first results on device fabrication are encouraging, which allow partial R2R manufacturing of flexible PSC (R2R coating of SnOx and perovskite, S2S for Spiro-OMeTAD and gold) with stabilized PCE of 12.6%, a remarkable value for these novel devices. This result can be considered an important milestone towards the production of efficient, low cost, lightweight, flexible PSC on large area.