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arXiv · 1711.06917

2D condensate of electrons and holes in ultrathin MoTe$_2$ photocells

Trevor B. Arp·Dennis Pleskot·Vivek Aji·Nathaniel M. Gabor
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Abstract

The electron-hole liquid, which features a macroscopic population of correlated electrons and holes, may offer a path to room temperature semiconductor devices that harness collective electronic phenomena. We report on the gas-to-liquid phase transition of electrons and holes in ultrathin molybdenum ditelluride photocells revealed through multi-parameter dynamic photoresponse microscopy (MPDPM). By combining rich visualization with comprehensive analysis of very large data sets acquired through MPDPM, we find that ultrafast laser excitation at a graphene-MoTe$_2$-graphene interface leads to the abrupt formation of ring-like spatial patterns in the photocurrent response as a function of increasing optical power at T = 297 K. These patterns, together with extreme sublinear power dependence and picosecond-scale photocurrent dynamics, provide strong evidence for the formation of a two-dimensional electron-hole condensate.

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Trevor B. Arp, Dennis Pleskot, Vivek Aji, Nathaniel M. Gabor. 2017-11-18. 2D condensate of electrons and holes in ultrathin MoTe$_2$ photocells. https://doi.org/10.1038/s41566-019-0349-y

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