Electro-Absorptive Quantum Dot Antenna Resolves Terahertz Lightwaves via Biased Stark Effect

Title data

Heindl, Moritz ; Zhu, Hua ; Bawendi, Moungi G. ; Herink, Georg:
Electro-Absorptive Quantum Dot Antenna Resolves Terahertz Lightwaves via Biased Stark Effect.
In: ACS Photonics. Vol. 11 (2024) Issue 1 . - pp. 13-17.
ISSN 2330-4022
DOI: https://doi.org/10.1021/acsphotonics.3c01464

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Abstract in another language

Semiconductor quantum dots offer highly flexible optoelectronic properties, rendering them attractive for a growing number of applications, including single-photon emitters, fluorescence microscopy, and display technology. Here, we report the realization of an electro-absorptive terahertz (THz) antenna based on colloidal semiconductor nanocrystals for the phase-resolved detection of infrared lightwaves. Introducing AC-biasing to symmetric nanocrystals, we break the symmetric response of the quantum-confined Stark effect (QCSE) to the direction of the THz field and obtain a polarity-sensitive observable. In particular, we analyze the nonlinear scaling of the QCSE and demonstrate that differential detection via bias-modulation yields a signal that linearly depends on the THz field strength. This THz antenna employs solution-processed quantum dots and enables an all-optical readout via absorption or emission, offering highly flexible implementations of THz sensing in the time domain.