Semiconductor Nanostructures for Energy Conversion
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an important role in tuning the properties of light-harvesting assemblies. John Morris and co-workers (DOI: 10.1021/ acsenergylett.7b00189) in their Perspective discuss how electronic structure, structural dynamics, and stability of Au/TiO2 systems affect the activity and selectivity toward wide ranging chemical transformations. Fundamental understanding of semiconductor−metal interactions is important in modulating reactions for utilization of renewable energy sources. Two other Perspectives focus on CsPbX3 nanocrystals (X = Cl, Br, I), which belong to the newest class of the QD family with tunable excited-state properties. The emission properties can be modulated with simple halide exchange or by doping with Mn2+ ions (Figure 1). Narayan Pradhan and co-workers (DOI: 10.1021/acsenergylett.7b00177) provide insights into the understanding of doping process, exciton confinement, and exciton energy transfer to dopant state and the impact of halide ion exchange on the photophysics of doped nanocrystals. Anshuman Nag and co-workers (DOI: 10.1021/acsenergylett.7b00191) in their Perspective (selected as Editors’ Choice) discuss how the unique electronic band structure of these perovskites contribute to the formation of defect tolerant CsPbX3 nanocrystals. They further discuss the future challenges in modifying optical properties by doping with Mn2+ or Bi3+ and creating heterostructures with metal nanoparticles. They also point out the need to improve optical properties of nonlead-based metal halide perovskites. Finally, Jillian Dempsey and co-workers (DOI: 10.1021/ acsenergylett.7b00063) review recent developments and key discoveries related to the excited-state proton-coupled electron transfer (ES-PCET) processes. It is important to understand
he size-, shape-, and composition-dependent properties of semiconductor and metal nanostructures have been in the forefront of advanced energy materials research. Whether designing a new electrocatalyst for fuel cells or a photocatalyst for solar fuels or development of next-generation solar cells, the nanostructure architecture plays an important role in energy conversion devices. The majority of new approaches developed through fundamental research in laboratories around the world have yet to make a direct impact on consumers. One major exception, however, is quantum dot or QD technology, adopted by the TV industry to incorporate semiconductor nanocrystals with enhanced color in the image display. In the coming years, we can expect many semiconductor nanostructurebased laboratory concepts to be incorporated in light energy conversion and display devices. This issue presents Perspectives highlighting new advances and challenges in utilizing nanostructure architectures for light energy conversion. Peter Reiss and co-workers (DOI: 10.1021/acsenergylett.7b00003) discuss newly emerging ternary semiconductors and their application in energy conversion and thermoelectrics. The ability to tune their band gap with size as well as composition is attractive in designing light-harvesting assemblies. In her Perspective, Emily Weiss (DOI: 10.1021/ acsenergylett.7b00061) discusses the strategies to control photoinduced energy and electron transfer in semiconductor nanocrystals through surface ligand chemistry. The surface bound molecules not only influence the optical properties of parent nanocrystals but also facilitate electron−hole transfer across the semiconductor interface. As we build more complex architectures for energy conversion, surface chemistry will play
Figure 1. (a−d) Emission of CsPbCl3, CsPbBr3, CsPbI3, and Mn:CsPbCl3 nanocrystals. (e) Band positions of CsPbX3 and Mn d-states. (f) Atomic model showing a typical Mn:CsPbCl3 crystal where Mn is placed in the position of Pb. Reprinted from Guria et al., ACS Energy Lett. 2017, 2, 1014−1021. Copyright 2017 American Chemical Society.
Published: May 12, 2017 © 2017 American Chemical Society
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DOI: 10.1021/acsenergylett.7b00329 ACS Energy Lett. 2017, 2, 1128−1129
Editorial
http://pubs.acs.org/journal/aelccp
ACS Energy Letters
Editorial
the intricacies of ES-PCET in order to design molecular systems that can mimic photosynthesis effectively. These processes hold promise in both solar fuel production and small molecule activation. The Perspectives and the Review published in this issue offer new opportunities to tackle new challenges in light energy conversion.
Prashant V. Kamat, Editor-in-Chief, ACS Energy Letters
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University of Notre Dame, Notre Dame, Indiana 46556, United States
AUTHOR INFORMATION
ORCID
Prashant V. Kamat: 0000-0002-2465-6819 Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS.
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DOI: 10.1021/acsenergylett.7b00329 ACS Energy Lett. 2017, 2, 1128−1129
