CHOISE: Breaking the Symmetry
Symmetry is captivating, but asymmetry is also intriguing. In life, we witness some objects exhibit right-handedness while others showcase left-handedness. This exciting concept known as chirality refers to objects that cannot be superimposed on their mirror images. From seashells to glucose and amino acids, chirality permeates various aspects of nature. In everyday life chirality plays an important role in liquid crystal displays, pharmaceutical manufacturing, cosmetics, agrochemicals, and the fragrance industry. The study of chirality in functional materials has yielded remarkable applications, and the Center for Hybrid Organic-Inorganic Semiconductors for Energy (CHOISE) is at the forefront of this research.
Established in 2018, CHOISE is an Energy Frontier Research Center (EFRC) led by the National Renewable Energy Laboratory (NREL). Comprised of experts from multiple academic and research institutions, the Center focuses on unraveling how light and electrons interact with emerging semiconductor compositions. With a primary goal of understanding and advancing hybrid organic-inorganic semiconductors, CHOISE strives to revolutionize technologies like photovoltaics and create new technologies exploiting the unique nature of organic-inorganic coupling in materials at the leading edge of science.
Continuous exploration and development of novel material systems drive technological progress. Hybrid organic–inorganic semiconductors, which combine organic and inorganic components within a single structure, offer unparalleled properties stemming from synergistic effects. One notable example is hybrid halide perovskites, which have garnered immense attention in the past decade for their potential applications in electronics, most notably as light absorbers in photovoltaic panels [1,2]. Hybrid perovskites are defined by the general formula ABX3, where A is an organic cation, B is a metal cation, and X is halide anion. These perovskites exhibit diverse functions, tunability, and solution processing capabilities, complementing traditional semiconductors like Silicon or Gallium Arsenide. Moreover, they possess fascinating spintronic properties and introduce structural chirality into perovskite structures, leading to the emergence of chiral perovskites with implications beyond our current fundamental understanding . Spintronics, derived from spin electronics, explores the utilization of both the electron's intrinsic spin and its accompanying magnetic moment, alongside its basic electronic charge, within solid-state devices. This field aims to go beyond traditional electronics, which focus solely on charge-based information processing.
CHOISE has played a pivotal role in the development of chiral perovskites. Most optoelectronic devices involve interactions between light and electric current. Photovoltaic (PV) panels are a perfect example, and perovskites are regularly making headlines in PV research, promising to bring nearly 50% more power to silicon panels. However, electrons also have a “spin” character that can be utilized to enable new technologies that we haven’t imagined yet. The Center achieved a groundbreaking feat by creating a solution-processed perovskite spin polarized light-emitting diode (SpinLED) that emits polarized light at room temperature without the need for a magnetic field, enabling a simpler and cost-effective technology . The SpinLED employs chiral perovskites, which act as electronic spin filters, enabling the emission of polarized light. In general, manipulating the spin properties in a semiconductor requires the use of ferromagnetic contacts under an applied magnetic field. However, chiral perovskites uniquely achieve spin control by polarizing the carrier spins as they pass through them. This opens a range of possibilities for futuristic technologies like 3D displays, holography, optical communication, and computing. Such spin-controlled semiconductors could offer high-fidelity computation, reducing electricity waste. Another exciting application of chiral perovskites lies in optical detectors for sensing polarized light. By integrating chiral perovskites into such detectors, the need for external polarizers can be eliminated, streamlining the sensing process and making it more efficient .
Chiral properties closely relate to the symmetry of the material, and to control the spin, one must break the structural symmetry. Chiral organic molecules in halide perovskites enable this symmetry breaking by distorting the crystal structure . Controlling the spin transport behavior of halide perovskites holds promise for designing energy-efficient and advanced devices. Recent research supported by CHOISE demonstrated the generation of spin current in chiral 2D halide perovskites through the chiral phonon-activated spin Seebeck effect (CPASS) . This effect occurs due the temperature difference, which causes certain vibrations called “phonons” in the chiral material to carry the spin information, resulting in the creation of a spin current. This groundbreaking combination of spintronics and thermoelectrics simplifies device architecture by eliminating the need for a ferromagnetic contact. CPASS can be observed in chiral semiconductors and chiral insulators at room temperature, paving the way for spin control and applications of halide perovskites in spintronic devices.
Although significant progress has been made in synthesizing various chiral perovskites and studying their chiroptical properties, understanding the intricacies of spin transport in these semiconductors is still in the early stages of exploration. Looking ahead, CHOISE aims to propel future advancements in this field through several exciting directions. These include compositional tuning for higher asymmetry, establishing universal guidelines for chirality transfer, and developing emissive chiral layers and crystals. Another ambitious goal is to integrate chiral perovskites with existing semiconductor technologies to further enhance their efficacy. As CHOISE continues its research journey, the future holds immense possibilities for chiral perovskites to drive technological advancements and shape a more sustainable and efficient future.
1. Lead-chelating hole-transport layers for efficient and stable perovskite minimodules C. Fei, N. Li, M. Wang, X. Wang, H. Gu, B. Chen, Z. Zhang, Z. Ni, H. Jiao, W. Xu, Z. Shi, Y. Yan and J. Huang, Science 380, 823-829 (2023)
This material is based upon work supported by the US Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under Solar Energy Technologies Office award no. DE-EE0009520. The research at Perotech, Inc., is supported by the Office of Naval Research under award no. N6833522C0122. The work at the University of Toledo was supported by the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science, within the US Department of Energy. DFT calculations used resources of the National Energy Research Scientific Computing Center (NERSC), a US Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under contract no. DE-AC02-05CH11231 using NERSC award BES-ERCAP0023945. The views expressed herein do not necessarily represent the views of the US Department of Energy or the United States government.
2. Surface reaction for efficient and stable inverted perovskite solar cells Q. Jiang, J. Tong, Y. Xian, R. A. Kerner, S. P. Dunfield, C. Xiao, R. A. Scheidt, D. Kuciauskas, X. Wang, M. P. Hautzinger, R. Tirawat, M. C. Beard, D. P. Fenning, J. J. Berry, B. W. Larson, Y. Yan and K. Zhu, Nature 611, 278-283 (2022)
The work was partially supported by the US Department of Energy under contract number DE-AC36-08GO28308 with Alliance for Sustainable Energy, Limited Liability Company (LLC), the Manager and Operator of the National Renewable Energy Laboratory. We acknowledge the support on first-principle calculations, surface reaction analysis, synthesis of 3-APyI2 and optoelectronic characterizations (for example, transient reflection and time-resolved microwave conductivity), from the Center for Hybrid Organic–Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science within the US Department of Energy. A portion of the research was performed using computational resources sponsored by the Department of Energy’s Office of Energy Efficiency and Renewable Energy and located at the National Renewable Energy Laboratory. We acknowledge the support on 3-APy surface treatment and the corresponding device fabrication and characterizations from DE-FOA-0002064 and award number DE-EE0008790, and the support on the general device and thin-film perovskite fabrication and characterizations from the Advanced Perovskite Cells and Modules programme of the National Center for Photovoltaics, funded by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Solar Energy Technologies Office. This work was also supported in part by the California Energy Commission EPIC programme, EPC-19-004. We acknowledge the use of facilities and instrumentation at the UC Irvine Materials Research Institute (IMRI), which is supported in part by the National Science Foundation through the UC Irvine Materials Research Science and Engineering Center (DMR-2011967). XPS and UPS were performed in part using instrumentation funded in part by the National Science Foundation Major Research Instrumentation Program under grant number CHE-1338173. We thank I. Tran for assistance with collecting the XPS and UPS data; and S. M. Rowland and L. M. Laurens for conducting the mass spectrometry measurements and structure assignments at the NREL Bioenergy Science Technologies directorate. The views expressed in the article do not necessarily represent the views of the DOE or the US Government.
3. Control of light, spin and charge with chiral metal halide semiconductors H. Lu, Z. V. Vardeny, M. C. Beard, Nature Reviews Chemistry 6, 470–485 (2022)
The work reviewed here is based on work supported as part of the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science, within the US Department of Energy through contract number DE-AC36-08G028308. Z.V.V. acknowledges funding from the DOE, Office of Science (grant no. DE-SC0014579). H.L. gratefully acknowledges funding from the Hong Kong University of Science and Technology (HKUST) School of Science (SSCI) and the Department of Chemistry via Project Funding R9270, as well as funding from the Early Career Scheme (grant no. 26300721) from the Hong Kong Research Grants Council (RGC). The views expressed in the article do not necessarily represent the views of the DOE or the US Government.
4. Chiral-induced spin selectivity enables a room-temperature spin light-emitting diode Y.-H. Kim, Y. Zhai, H. Lu, X. Pan, C. Xiao, E. A. Gaulding, S. P. Harvey, J. J. Berry, Z. V. Vardeny, J. M. Luther, M. C. Beard, Science 371, 1129-1133 (2021)
The authors acknowledge L. M. Wheeler for help with photoluminescence measurements, C. Zou for help with LED measurements, and X. Chen for help with CP-EL measurements. We gratefully acknowledge funding as part of the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science, within the U.S. Department of Energy through contract no. DE-AC36-08G028308. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. government.
5. Direct detection of circularly polarized light using chiral copper chloride–carbon nanotube heterostructures. J. Hao, H. Lu, L. Mao, X. Chen, M. C. Beard, J. L. Blackburn, ACS Nano 15, 7608–7617 (2021)
This work was supported by the Center for Hybrid Organic Inorganic Semiconductors for Energy (CHOISE) an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science within the U.S. Department of Energy. This work was authored, in part, by Alliance for Sustainable Energy LLC, the manager and operator of the National Renewable Energy Laboratory for the U.S. DOE under Contract No. DE-AC36-08G028308. L.M.’s work at UCSB was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Grant No. SC0012541. We also thank Dr. Tianyang Li for helping with the XRD measurement. The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. government purposes.
6. Organic-to-inorganic structural chirality transfer in a 2D hybrid perovskite and impact on Rashba-Dresselhaus spin-orbit coupling M. K. Jana, R. Song, H. Liu, D. R. Khanal, S. M. Janke, R. Zhao, C. Liu, Z. Valy Vardeny, V. Blum and D. B. Mitzi, Nature Communications 11, 4699 (2020)
We acknowledge funding from the Center for Hybrid Organic-Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the Office of Basic Energy Sciences, Office of Science within the U.S. Department of Energy (DOE) through contract number DE-AC36-08G028308. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish, or reproduce the published form of this work or allow others to do so, for U.S. Government purposes. C.L. was supported by the National Science Foundation under Award Number DMR-1729297. An award of computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357. This research also used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy (DOE) Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. S.M.J. thanks the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for a postdoctoral fellowship, grant number 393196393. We thank Matthew C. Beard, Evan Lafalce, Sven Lidin, Tianyang Li, and Pete Sercel for useful discussions. We also thank Xinyi Lin for help with the graphical plotting of spin texture output.
7. Chiral-phonon-activated spin Seebeck effect. K. Kim, E. Vetter, L. Yan, C. Yang, Z. Wang, R. Sun, Y. Yang, A. H. Comstock, X. Li, J. Zhou, L. Zhang, W. You, D. Sun, J. Liu, Nature Materials, 22, 322–328 (2023)
J.L. acknowledges the financial support from the National Science Foundation under award number CBET 1943813 for the ultrafast measurements, thermal characterizations and thermal modelling. D.S. acknowledges the financial support provided by the US Department of Energy, Office of Science, under the grant number DE-SC0020992 for the device fabrications. D.S. and W.Y. acknowledge the support through the Center for Hybrid Organic–Inorganic Semiconductors for Energy (CHOISE), an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences for material synthesis, thin-film preparations and magnetic characterizations. J.L. acknowledges partial financial support from the North Carolina Space Grant New Investigator Award for the student aids. D.S. and J.L. also acknowledge the partial financial support from the North Carolina State University Research and Innovation Seed Funding for the student aids. The X-ray diffraction of the perovskite thin films in this work was performed at the Chapel Hill Analytical and Nanofabrication Laboratory (CHANL), a member of the North Carolina Research Triangle Nanotechnology Network (RTNN), which is supported by the National Science Foundation, grant ECCS-1542015, as part of the National Nanotechnology Coordinated Infrastructure (NNCI). The circular dichroism measurements were performed at the UNC Macromolecular Interactions Facility supported by the National Cancer Institute of the National Institutes of Health under award number P30CA016086.