Monolithic Perovskite/Silicon Tandems with >28% Efficiency: Role of Silicon‐Surface Texture on Perovskite Properties

Abstract

Textured silicon wafers used in silicon solar cell manufacturing offer superior light trapping, which is a critical enabler for high-performance photovoltaics. A similar optical benefit can be obtained in monolithic perovskite/silicon tandem solar cells, enhancing the current output of the silicon bottom cell. Yet, such complex silicon surfaces may affect the structural and optoelectronic properties of the overlying perovskite films. Here, through extensive characterization based on optical and microstructural spectroscopy, it is found that the main effect of such substrate morphology lies in an altering of the photoluminescence response of the perovskite, which is associated with thickness variations of the perovskite, rather than lattice strain or compositional changes. With this understanding, the design of high-performance perovskite/silicon tandems is rationalized, yielding certified power conversion efficiencies of >28%.

Room Temperature Epitaxy of CH3NH3PbI3 Halide Perovskite by Pulsed Laser Deposition

“…Moreover, as the film thickness approaches its critical thickness, the reduced effect of the substrate on the epitaxial strain allows the formation of additional defects such as dislocations, likely resulting in an increased FWHM for the 70 nm films 43 . Notably, this shift cannot be explained by the reabsorption of emitted photons for the thicker films 45,46 . Further, we estimated the optoelectronic quality of the epitaxial film, by extracting the Urbach energy (EU) from the PL spectrum.…”

Influence of thermal annealing on microstructure, energetic landscape and device performance of P3HT:PCBM-based organic solar cells

“…The active layer films were deposited via spin-coated on a quartz substrate. The samples were excited from the top surface with a 532 nm laser and focused through a microscope objective (20 times) with an exposure time of 5 s and power of 1500 W. Hyperspectral images were analyzed using PHySpecV2 software provided by Photon etc [54,55].…”

Overcoming Two Key Challenges in Monolithic Perovskite‐Silicon Tandem Solar Cell Development: Wide Bandgap and Textured Substrate—A Comprehensive Review

“…They discovered that the perovskites’ morphological properties correlate with perovskites’ PL response that changes with the alteration in the perovskite layer's thickness. [ 179 ] They coated a micrometer‐thick perovskite layer on different silicon‐textured surfaces (Figure 11D). Figure 11E,F illustrates the correlation between the PL emission and the morphology.…”