Brongersma Group Plasmonics and Photonics at Stanford University

@article{lee2023multi,

title = {Multi‐resonant Mie Resonator Arrays for Broadband Light Trapping in Ultrathin c‐Si Solar Cells},

author = {Nayeun Lee and Muyu Xue and Jiho Hong and Jorik van de Groep and Mark L Brongersma},

doi = {10.1002/adma.202210941},

year  = {2023},

date = {2023-05-02},

urldate = {2023-05-02},

journal = {Advanced Materials},

pages = {2210941},

abstract = {Effective photon management is critical to realize high power conversion efficiencies for thin crystalline Si (c-Si) solar cells. Standard few-100-µm-thick bulk cells achieve light trapping with macroscopic surface textures covered by thin, continuous antireflection coatings. Such sizeable textures are challenging to implement on ultrathin cells. Here, we illustrate how nanoscale Mie-resonator-arrays with a bi-modal size distribution support multiple resonances that can work in concert to achieve simultaneous antireflection and light-trapping across the broad solar spectrum. We experimentally demonstrate the effectiveness of these light-trapping antireflection coatings (LARCs) on a 2.8-µm-thick c-Si solar cell. The measured short-circuit current and corresponding power conversion efficiency are notably improved, achieving efficiencies as high as 11.2%. Measurements of the saturation current density on completed cells indicate that thermal oxides can effectively limit surface recombination. The presented design principles are applicable to a wide range of solar cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Zubritskaya2023,

title = {Dynamically Tunable Optical Cavities with Embedded Nematic Liquid Crystalline Networks},

author = {Irina Zubritskaya and Rafael Cichelero and Ihar Faniayeu and Daniele Martella and Sara Nocentini and Per Rudquist and Diederik Sybolt Wiersma and Mark L. Brongersma},

doi = {10.1002/adma.202209152},

year  = {2023},

date = {2023-01-22},

urldate = {2023-01-22},

journal = {Advanced Materials},

pages = {2209152},

abstract = {Abstract Tunable metal\textendashinsulator\textendashmetal (MIM) Fabry\textendashP\'{e}rot (FP) cavities that can dynamically control light enable novel sensing, imaging and display applications. However, the realization of dynamic cavities incorporating stimuli-responsive materials poses a significant engineering challenge. Current approaches rely on refractive index modulation and suffer from low dynamic tunability, high losses, and limited spectral ranges, and require liquid and hazardous materials for operation. To overcome these challenges, a new tuning mechanism employing reversible mechanical adaptations of a polymer network is proposed, and dynamic tuning of optical resonances is demonstrated. Solid-state temperature-responsive optical coatings are developed by preparing a monodomain nematic liquid crystalline network (LCN) and are incorporated between metallic mirrors to form active optical microcavities. LCN microcavities offer large, reversible and highly linear spectral tuning of FP resonances reaching wavelength-shifts up to 40 nm via thermomechanical actuation while featuring outstanding repeatability and precision over more than 100 heating\textendashcooling cycles. This degree of tunability allows for reversible switching between the reflective and the absorbing states of the device over the entire visible and near-infrared spectral regions, reaching large changes in reflectance with modulation efficiency ΔR = 79%.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hong:23,

title = {Nonlocal metasurface for circularly polarized light detection},

author = {Jiho Hong and Jorik van de Groep and Nayeun Lee and Soo Jin Kim and Philippe Lalanne and Pieter G. Kik and Mark L. Brongersma},

doi = {10.1364/OPTICA.468252},

year  = {2023},

date = {2023-01-20},

journal = {Optica},

volume = {10},

number = {1},

pages = {134-141},

abstract = {Modern-day sensing and imaging applications increasingly rely on accurate measurements of the primary physical quantities associated with light waves: intensity, wavelength, directionality, and polarization. These are conventionally performed with a series of bulky optical elements, but recently, it has been recognized that optical resonances in nanostructures can be engineered to achieve selective photodetection of light waves with a specific set of predetermined properties. Here, we theoretically illustrate how a thin silicon layer can be patterned into a dislocated nanowire-array that affords detection of circularly polarized light with an efficiency that reaches the theoretical limit for circular dichroism of a planar detector in a symmetric external environment. The presence of a periodic arrangement of dislocations is essential in achieving such unparalleled performance as they enable selective excitation of nonlocal, guided-mode resonances for one handedness of light. We also experimentally demonstrate compact, high-performance chiral photodetectors created from these dislocated nanowire-arrays. This work highlights the critical role defects can play in enabling new nanophotonic functions and devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ji2022quantitative,

title = {Quantitative phase contrast imaging with a nonlocal angle-selective metasurface},

author = {Anqi Ji and Jung-Hwan Song and Qitong Li and Fenghao Xu and Ching-Ting Tsai and Richard C Tiberio and Bianxiao Cui and Philippe Lalanne and Pieter G Kik and David AB Miller and Mark L Brongersma},

year  = {2022},

date = {2022-12-21},

urldate = {2022-12-21},

journal = {Nature Communications},

volume = {13},

issue = {1},

pages = {1-7},

abstract = {Phase contrast microscopy has played a central role in the development of modern biology, geology, and nanotechnology. It can visualize the structure of translucent objects that remains hidden in regular optical microscopes. The optical layout of a phase contrast microscope is based on a 4 f image processing setup and has essentially remained unchanged since its invention by Zernike in the early 1930s. Here, we propose a conceptually new approach to phase contrast imaging that harnesses the non-local optical response of a guided-mode-resonator metasurface. We highlight its benefits and demonstrate the imaging of various phase objects, including biological cells, polymeric nanostructures, and transparent metasurfaces. Our results showcase that the addition of this non-local metasurface to a conventional microscope enables quantitative phase contrast imaging with a 0.02π phase accuracy. At a high level, this work adds to the growing body of research aimed at the use of metasurfaces for analog optical computing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}