Design of Nanostructured Solar Cells Using Coupled Optical and Electrical Modeling Michael G. Deceglie † , Vivian E. Ferry ‡ , A. Paul Alivisatos ‡ , and Harry A. Atwater* ,† Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, California 91125, United States Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States Abstract: Nanostructured light trapping has emerged as a promising route toward improved efficiency in solar cells. We use coupled optical and electrical modeling to guide optimization of such nanostructures. We study thin-film n-i-p a-Si:H devices and demonstrate that nanostructures can be tailored to minimize absorption in the doped a-Si:H, improving carrier collection efficiency. This suggests a method for device optimization in which optical design not only maximizes absorption, but also ensures resulting carriers are efficiently collected. Keywords: Thin film solar cells, plasmon, nanophotonic, light trapping, simulation, device physics, silicon, photovoltaics In order to maximize solar cell efficiency, it is necessary to optimize both the electrical device physics and the optical absorption of the device. Typically, these two problems are treated separately,

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Design of Nanostructured Solar Cells Using Coupled Optical and Electrical Modeling - eScholarship

Optimal Interfacial Engineering with Different Length of Alkylammonium Halide for Efficient and Stable Perovskite Solar Cells

Infrared (IR) adaptation phenomena are ubiquitous in nature and biological systems. Taking inspiration from natural creatures, researchers have devoted extensive efforts for developing advanced IR adaptive materials and exploring their applications in areas of smart camouflage, thermal energy management, biomedical science, and many other IR-related technological fields. Herein, an up-to-date review is provided on the recent advancements of bioinspired IR adaptive materials and their promising applications. First an overview of IR adaptation in nature and advanced artificial IR technologies is presented. Recent endeavors are then introduced toward developing bioinspired adaptive materials for IR camouflage and IR radiative cooling. According to the Stefan-Boltzmann law, IR camouflage can be realized by either emissivity engineering or thermal cloaks. IR radiative cooling can maximize the thermal radiation of an object through an IR atmospheric transparency window, and thus holds great potential for use in energy-efficient green buildings and smart personal thermal management systems. Recent advances in bioinspired adaptive materials for emerging near-IR (NIR) applications are also discussed, including NIR-triggered biological technologies, NIR light-fueled soft robotics, and NIR light-driven supramolecular nanosystems. This review concludes with a perspective on the challenges and opportunities for the future development of bioinspired IR adaptive materials.

Beyond the Visible: Bioinspired Infrared Adaptive Materials.

Atomically thin transition metal dichalcogenides have emerged as promising candidates for sensitive photodetection. Here, we report a photoconductivity study of biased mono- and bilayer molybdenum disulfide field-effect transistors. We identify photovoltaic and photoconductive effects, which both show strong photogain. The photovoltaic effect is described as a shift in transistor threshold voltage due to charge transfer from the channel to nearby molecules, including SiO2 surface-bound water. The photoconductive effect is attributed to the trapping of carriers in band tail states in the molybdenum disulfide itself. A simple model is presented that reproduces our experimental observations, such as the dependence on incident optical power and gate voltage. Our findings offer design and engineering strategies for atomically thin molybdenum disulfide photodetectors, and we anticipate that the results are generalizable to other transition metal dichalcogenides as well.

Mechanisms of photoconductivity in atomically thin MoS2

Spectrally selective approaches for passive cooling of solar cells: A review

We propose a colored radiative cooler assisted by optical Tamm resonance, which features the high-performance cooling effect and high-purity subtractive primary colors (CMY) simultaneously. By deve...

Colored Radiative Cooler under Optical Tamm Resonance

Passive radiative cooling technology has attracted extensive attention as it addresses the potential applications in effectively cooling photovoltaics and related systems. Here, we performed comprehensive multidimensional and multiphysical opto-electro-thermal (OET) modeling, which was used to design a silicon-based radiative cooling system for a solar cell (SC). Our study simultaneously takes into account the coupled effects of the radiative cooling characteristics, carrier thermodynamics, and electrodynamic behaviors of SCs in the spatial and frequency domains. Based on a comprehensive photonic design, we presented a radiative cooler with near-ideal spectral selectivity from the sunlight to the infrared band. The fundamental OET physical mechanisms and the effect of temperature on the performance of SCs were explored. A comparable study on the performance parameters of the SCs with and without a radiative cooler was formulated, which revealed that the SC temperature can be reduced by over 10 °C and the absolute power conversion efficiency (PCE) can be increased by 0.45% after employing a photonic radiative cooler. Our OET study provides a ready method to explore the comprehensive OET physics in photovoltaic systems.

Radiative cooling of solar cells: opto-electro-thermal physics and modeling.

A universal close-space annealing strategy towards high-quality perovskite absorbers enabling efficient all-perovskite tandem solar cells

Perovskite Solar Cells: Optoelectronic Simulation and Optimization

Organic-inorganic heterojunction perovskite solar cell (PSC) is promising for low-cost and high-performance photovoltaics. To further promote the performance of PSCs, understanding and controlling the underneath photoconversion mechanisms are highly necessary. Here, we present a comprehensive opto-electro-thermal (OET) study on the heterojunction PSCs by quantitatively addressing the coupled optical, carrier transport, and thermodynamic behaviors within the device. With achieving a good agreement with the experiment, we theoretically explore the thermodynamic mechanisms involving the energy conversions and focus especially on the origins of the various energy losses in PSCs. We summarize six categories of microscopic heat conversion processes in the heterojunction PSC, where the Joule and Peltier heats can be defined as the intrinsic losses in PSCs. Moreover, we also discuss the possible manipulation methods to decrease the energy losses, for example, by tailoring the doping concentration and energy-level alignment. An exemplified OET optimization is also presented, which predicts that the PCE of the fabricated PSC can be enhanced from 21.37% to 23.84%.

Yidan An

Papers

Colored Radiative Cooler under Optical Tamm Resonance

Radiative cooling of solar cells: opto-electro-thermal physics and modeling.

A universal close-space annealing strategy towards high-quality perovskite absorbers enabling efficient all-perovskite tandem solar cells

Perovskite Solar Cells: Optoelectronic Simulation and Optimization

Heterojunction Perovskite Solar Cells: Opto-Electro-Thermal Physics, Modeling, and Experiment.