Affiliation:
1. Department of Mechanical & Materials Engineering University of Nebraska‐Lincoln Lincoln NE 68588 USA
2. Center for Functional Nanomaterials Brookhaven National Laboratory Upton NY 11973 USA
3. Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37830 USA
4. Department of Materials Science & Engineering University of Virginia Charlottesville VA 22904 USA
5. Department of Electrical & Computer Engineering University of Nebraska‐Lincoln Lincoln NE 68588 USA
Abstract
AbstractLateral heterostructures combining two multilayer group IV chalcogenide van der Waals semiconductors have attracted interest for optoelectronics, twistronics, and valleytronics, owing to their structural anisotropy, bulk‐like electronic properties, enhanced optical thickness, and vertical interfaces enabling in‐plane charge manipulation/separation, perpendicular to the trajectory of incident light. Group IV monochalcogenides support propagating photonic waveguide modes, but their interference gives rise to complex light emission patterns throughout the visible/near‐infrared range both in uniform flakes and single‐interface lateral heterostructures. Here, this work demonstrates the judicious integration of pure and alloyed monochalcogenide crystals into multimaterial heterostructures with unique photonic properties, notably the ability to select photonic modes with targeted discrete energies through geometric factors rather than band engineering. SnS‐GeS1−xSex‐GeSe‐GeS1−xSex heterostructures with a GeS1−xSex active layer sandwiched laterally between GeSe and SnS, semiconductors with similar optical constants but smaller bandgaps, were designed and realized via sequential vapor transport synthesis. Raman spectroscopy, electron microscopy/diffraction, and energy‐dispersive X‐ray spectroscopy confirm a high crystal quality of the laterally stitched components with sharp interfaces. Nanometer‐scale cathodoluminescence spectroscopy provides evidence for a facile transfer of electron–hole pairs across the lateral interfaces and demonstrates the selection of photon emission at discrete energies in the laterally embedded active (GeS1−xSex) part of the heterostructure.
Funder
Brookhaven National Laboratory
Basic Energy Sciences
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry