Soft Lithography for Manufacturing Scalable Perovskite Metasurfaces with Enhanced Emission and Absorption

Abstract

Organic–inorganic hybrid perovskites have emerged in recent years as a promising alternative to silicon solar cells and other optoelectronic devices, mostly due to their high photon yields, long carrier lifetime, adjustable bandgap, and other merits. While patterning photonic nanostructures onto their inorganic counterparts is well established to augment their capabilities, lack of compatibility with conventional lithography techniques hinders the implementation of those principles with perovskites. Hereby, the fabrication of MAPbI3 nanophotonic structures such as nanoscale metasurfaces is demonstrated via soft lithography, a method in which the patterning is done when the perovskite is not fully crystallized, allowing for crystallization within the mold with the end result of facile and unharmful imprinting of sub‐micron features onto perovskite thin films, over large areas and with the potential to scale up in a seamless way. By doing so, a substantial increase in light absorption as well as twofold photoluminescence enhancement from the perovskite thin film is shown. These results are supported by spectral and lifetime measurements. This method is pertinent to many device configurations and can assist in realizing the future of high‐efficiency perovskite‐based devices, including solar cells, LEDs, lasers, and more.

Luminescence enhancement effects on nanostructured perovskite thin films for Er/Yb-doped solar cells

“…We will also show that the presence of roughness and defects generate fluctuations and hot spots that modify the luminescence. Although the structures have been fabricated on a sub-millimeter scale, they can also be created on much larger scales using, for instance, interference lithography or soft lithography 42,43 .…”

“…Although structures have been fabricated on a submillimeter scale, they can also be created on much larger scales using, for instance, interference lithography or so lithography. 42,43 B Techniques and methods…”

Photonic Structuration of Hybrid Inverse-Opal TiO2—Perovskite Layers for Enhanced Light Absorption in Solar Cells

“…33 The beneficial impact of photonic structuration on optical performances of PSCs has been highlighted in terms of light trapping and harvesting capacity, thanks to the fine tuning capacity of the difference of optical constants directly at the interface; assembled PV devices are also shown to present improved properties of charge injection, transportation, and collection efficiency. 15,22,23 The exact morphology, structure, and organization degree of such TiO 2 "scaffolds" as well as their processing method-ologiesthat may involve soft (block-polymer templating) 16 and hard (solid spheres assembly) 17 lithographic approaches, nanoimprinting processes, 13,18,19 anodization treatments, 34 etc.have been further discussed as these crucially influence both optical and electronic properties of the PSCs. 15,22,23 In comparison with unstructured mesoporous layers consisting of randomly packed spherical TiO 2 nanoparticles, one-(1D), two-(2D), and three-dimensional (3D) photonically structured layers specifically allow not only for increased and more organized porosity, achieving more controlled perovskite infiltration, but also for improved carrier transportation and recombination behavior.…”

“…Numerous methodologies of photonic structuration have been reported in the literature, all aiming at optimizing the light–matter interactions from appropriate texturing of a photoactive material or device constituent. Various top-down and bottom-up approaches and protocols, including soft templating with polymer surfactants, nanosphere lithography, or nanoimprinting, , have been used for photonically structuring the photoactive material with the perspective of enhancing performances of the PV devices in terms of light harvesting, photocurrent generation, and mitigation of lead content in PSCs. Noteworthily, the recent simulation-based study conducted by Schmager et al has shown that the design of optimized nanophotonic perovskite layers could lead to a 5–6% increased photocurrent together with enhanced light harvesting efficiency …”

“…The exact morphology, structure, and organization degree of such TiO 2 “scaffolds” as well as their processing methodologiesthat may involve soft (block-polymer templating) and hard (solid spheres assembly) lithographic approaches, nanoimprinting processes, ,, anodization treatments, etc.have been further discussed as these crucially influence both optical and electronic properties of the PSCs. ,, In comparison with unstructured mesoporous layers consisting of randomly packed spherical TiO 2 nanoparticles, one- (1D), two- (2D), and three-dimensional (3D) photonically structured layers specifically allow not only for increased and more organized porosity, achieving more controlled perovskite infiltration, but also for improved carrier transportation and recombination behavior.…”