Scalable Graphene‐on‐Organometal Halide Perovskite Heterostructure Fabricated by Dry Transfer

Abstract

Graphene, a single layer conductor, can be combined with other functional materials for building efficient optoelectronic devices. However, transferring large‐area graphene onto another material often involves dipping the material into water and other solvents. This process is incompatible with water‐sensitive materials such as organometal halide perovskites. Here, a dry method is used and succeeded, for the first time, in stacking centimeter‐sized graphene directly onto methylammonium lead iodide thin films without exposing the perovskite film to any liquid. Photoemission spectroscopy and nanosecond time‐resolved photoelectrical measurement show that the graphene/perovskite interface does not contain significant amount of contaminants and sustain efficient interfacial electron transfer. The use of this method in fabricating graphene‐on‐perovskite photodetectors is further demonstrated. Besides a better photoresponsivity compared to detectors fabricated by the conventional perovskite‐on‐graphene structure, this dry transfer method provides a scalable pathway to incorporate graphene in multilayer devices based on water‐sensitive materials.

Wafer‐scale vertical van der Waals heterostructures

“…71 A centimeter-scale graphene/perovskite vdWH was also fabricated through vacuum dry transfer method to avoid deterioration of water/oxygen-sensitive perovskite layer. 72 Inkjet printing is an efficient way to manufacture large-scale heterostructures on wafers with low cost. [73][74][75] As long as the stable and homogeneous nanosheet ink is arranged (the ink applicability is judged by parameter Z, affected by ink viscosity, surface tension, density and nozzle diameter 76,77 ), the large-scale vdWHs arrays can be fabricated simply by printing the materials layer by layer through a printer.…”

“…36,65,82 When chemically unstable materials are involved, dry transfer with appropriate support layer and stack in vacuum is a suitable way to construct high quality vdWHs with few contaminations. 67,68,72 However, for wafer-scale transfer of ultrathin 2D materials, some artificial defects are introduced inevitably by external strain from the supporting layer, including but not limited to wrinkles, ripples, cracks and bubbles, which will downgrade the quality of vdWHs. 9,83,84 Keeping low transferring speed or using a linear guide rail to avoid breaking the fragile components is an applicable strategy to construct vdWHs with higher quality, but the production efficiency will be decreased.…”

“…When the 2D materials were stacked in vacuum through TRT‐assisted dry transfer, a 5‐cm‐scale three‐layer overlapping MoS 2 film was obtained with less interlayer contamination (Figure 2D). 71 A centimeter‐scale graphene/perovskite vdWH was also fabricated through vacuum dry transfer method to avoid deterioration of water/oxygen‐sensitive perovskite layer 72 …”

“…Wet transfer and stacking with the aid of polymer support layers and separation by the function of etchant or water is the most common method 36,65,82 . When chemically unstable materials are involved, dry transfer with appropriate support layer and stack in vacuum is a suitable way to construct high quality vdWHs with few contaminations 67,68,72 . However, for wafer‐scale transfer of ultrathin 2D materials, some artificial defects are introduced inevitably by external strain from the supporting layer, including but not limited to wrinkles, ripples, cracks and bubbles, which will downgrade the quality of vdWHs 9,83,84 .…”

Review of fabrication methods of large-area transparent graphene electrodes for industry

“…Furthermore, the target substrate should be rigid and clean in order to achieve a good conformal transfer. A modified version of this involves a secondary release layer in between the stamp and the graphene [118][119][120], allowing the transfer to a wider range of substrates.…”