Colored Silicon Heterojunction Solar Cells Exceeding 23.5% Efficiency Enabled by Luminescent Down‐Shift Quantum Dots

Abstract

photovoltaic modules are widely used in ground-mounted solar power plants or rooftop PV installations. [2,3] However, there is increasing emphasis on the visual aesthetics of solar modules, [4,5] such as building-integrated photovoltaics (BIPV), which exhibit the potential to both power and decorate urban architecture owing to their low space requirements. Colored PV panels are typically mounted on the roof or glass facades of buildings which improve the visual aesthetics of the building. Moreover, aesthetically designed PV technology is also popular in productintegrated solar cells, where it can power electronics and simultaneously meet the overall visual design of the product. [6] The light escaping from the cell surface causes a colored appearance due to cell current loss owing to less light absorption. Thus, a tradeoff between colored appearance and device performance should be realized. Therefore, in colored PV panels, it is challenging to improve the visual aesthetics while preserving initial power conversion efficiency (PCE). [7] One promising method is to minimize the reflection range of colored PV cells to meet high color purity and low photon loss.Most PV cells exhibit a black or dark-blue appearance because of the low-reflection optical design for a high current Colored solar panels, realized by depositing various reflection layers or structures, are emerging as power sources for building with visual aesthetics. However, these panels suffer from reduced photocurrent generation due to the less efficient light harvesting from visible light reflection and degraded power conversion efficiency (PCE). Here, color-patterned silicon heterojunction solar cells are achieved by incorporating luminescent quantum dots (QDs) with high quantum yields as light converters to realize an asthenic appearance with high PCE. It is found that large bandgap (blue) QD layers can convert UV light into visible light, which can notably alleviate the parasitic absorption by the front indium tin oxide and doped amorphous silicon. Additionally, a universal optical path model is proposed to understand the light transmission process, which is suitable for luminescent down-shift devices. In this study, solar cells with a PCE exceeding 23.5% are achieved using the combination of a blue QD layer and a top low refractive index antireflection layer. Based on our best knoledge,the obtained PCE is the highest for a color-patterned solar cell. The results suggest an enhanced strategy involving incorporation of luminescent QDs with an optical path design for high-performance photovoltaic panels with visual aesthetics.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202208042.

Dewetting-Assisted Patterning: A Lithography-Free Route to Synthesize Black and Colored Silicon

“…Additionally, the high reflectance of bulk silicon surfaces can be suppressed down to a few percent using structured black Si, which is highly relevant for solar conversion systems: ,− For example, nonuniform black VA-SiNWs films were used as an antireflection coating with a high angular acceptance to improve the efficiency of state-of-the-art silicon solar cells built with interdigitated back-contacts. , Instead, properly nanostructured colored silicon could be used as a wavelength selective absorption layer to produce silicon solar cells with well-defined and vivid colors. Although yet unexplored, such colored silicon could provide another path to engineer the aesthetics of silicon solar cells for colored photovoltaics. , Since the optical properties of both black and colored silicon are strongly geometry dependent, finding cost-effective methods to reliably nanostructure silicon is essential.…”

“…Although yet unexplored, such colored silicon could provide another path to engineer the aesthetics of silicon solar cells for colored photovoltaics. 25,26 Since the optical properties of both black and colored silicon are strongly geometry dependent, finding cost-effective methods to reliably nanostructure silicon is essential. The fabrication of VA-SiNW arrays can be achieved via bottom-up vapor−liquid solid (VLS) synthesis 27 and top-down techniques such as reactive-ion etching (RIE) 14,28 and metalassisted chemical etching (MACE).…”

“…Although yet unexplored, such colored silicon could provide another path to engineer the aesthetics of silicon solar cells for colored photovoltaics. 25 , 26 Since the optical properties of both black and colored silicon are strongly geometry dependent, finding cost-effective methods to reliably nanostructure silicon is essential.…”

Comparing single-, double- and triple-layer anti-reflection coatings for ultra-low reflectance in silicon heterojunction solar cells

“…Silicon heterojunction (SHJ) solar cells (SCs) have recently attracted considerable attention due to their great potential for high theoretical ultimate efficiency and low cost in industrialscale manufacturing. [1][2][3] With the demand for large-scale commercialization, world records keep being broken for the efficiency of SHJ SCs. 4) To achieve high efficiency, SHJ SCs must make optimal use of sunlight.…”

Nonradiative Energy Transfer Enables a hv < Eg Response of Perovskite Quantum Dots in Si-Based Inorganic–Organic Hybrid Solar Cells

“…For example, the perovskite thin film materials, attractive in recent years for their high spectral response, and low cost as well as a high initial performance of a single junction, − can be used as the top cell, to form perovskite/Si tandem solar cells. , However, there are lots of challenges in designing/fabricating tandem/multijunction, such as photocurrent matching, tunnel junction, and so on. , Besides, the high-energy photons, particularly in the ultraviolet (UV) wavelength region, which have energy much higher than the bandgap, are mostly absorbed nearly at the surface of Si devices but provide few effective carriers for device performance because of more defect states at the interface . Therefore, exploring an easier/simpler way to efficiently utilize these high-energy photons of short wavelength even the UV region for higher performance is needed, such as using light-converting layers in front of the c-Si solar cells may be a promising approach. − …”