Quantum efficiency scaling by cascaded Ge multi-stage tunnel junctions

Hack M, Korner R, Schwarz D, Daus A, Schulze J, Oehme M (2025)

Publication Language: English

Publication Type: Journal article

Publication year: 2025

Journal

Journal of Lightwave Technology Optical Society of America

Book Volume: 43

Pages Range: 8825-8831

Journal Issue: 18

DOI: 10.1109/JLT.2025.3589018

Abstract

We present the growth and characterization of Ge-Zener-Emitters (Ge-ZE) with up to four cascaded multi-stage tunnel junctions (XTJ = 4), and demonstrate significant improvements in both external quantum efficiency (EQE) and wall-plug efficiency. Room-temperature measurements confirm a systematic increase in forward turn-on voltage per junction, while low-temperature operation reveals deviations in voltage scaling for XTJ = 4, impacting device efficiency. Through optoelectronic characterization, we confirm successful EQE scaling but also identify limitations arising from heat dissipation and device degradation at high current densities. Notably, we observe an emission rate exceeding theoretical expectations, indicating the potential presence of amplified spontaneous emission. For quantum photonic integrated circuit applications, which require a minimum optical power Popt ≥ 200 nW, we demonstrate that cascaded multi-stage tunnel junctions enable sufficient power generation, achieving Popt = 284 nW at a wavelength λ = 1424 nm under pulsed excitation.

Authors with CRIS profile

Jörg Schulze Lehrstuhl für Elektronische Bauelemente

Involved external institutions

Universität Stuttgart DE Germany (DE) TRUMPF Photonic Components / Philips Photonics / U-L-M Photonics GmbH DE Germany (DE)

How to cite

APA:

Hack, M., Korner, R., Schwarz, D., Daus, A., Schulze, J., & Oehme, M. (2025). Quantum efficiency scaling by cascaded Ge multi-stage tunnel junctions. Journal of Lightwave Technology, 43(18), 8825-8831. https://doi.org/10.1109/JLT.2025.3589018

MLA:

Hack, Michael, et al. "Quantum efficiency scaling by cascaded Ge multi-stage tunnel junctions." Journal of Lightwave Technology 43.18 (2025): 8825-8831.

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