Author(s): Li, SL (Li, Shulun); Shang, XJ (Shang, Xiangjun); Chen, Y (Chen, Yao); Su, XB (Su, Xiangbin); Hao, HM (Hao, Huiming); Liu, HQ (Liu, Hanqing); Zhang, Y (Zhang, Yu); Ni, HQ (Ni, Haiqiao); Niu, ZC (Niu, Zhichuan)

Source: NANOMATERIALS Volume: 11 Issue: 5 Article Number: 1136 DOI: 10.3390/nano11051136 Published: MAY 2021

Abstract: Uniform arrays of three shapes (gauss, hat, and peak) of GaAs microlenses (MLs) by wetetching are demonstrated, similar to 200 nm spatial isolation of epitaxial single QDs embedded (lambda: 890-990 nm) and broadband (Delta lambda similar to 80 nm) enhancement of their quantum light extraction are obtained, which is also suitable for telecom-band epitaxial QDs. Combined with the bottom distributed Bragg reflector, the hat-shaped ML forms a cavity and achieves the best enhancement: extraction efficiency of 26%, Purcell factor of 2 and single-photon count rate of 7 x 10(6) counts per second at the first lens; while the gauss-shaped ML shows a broader band (e.g., longer lambda) enhancement. In the MLs, single QDs with featured exciton emissions are observed, whose time correlations prove single-photon emission with multi-photon probability g((2)) (0) = 0.02; some QDs show both biexciton XX and exciton X emissions and exhibit a perfect cascade feature. This work could pave a step towards a scalable array of QD single-photon sources and the application of QD photon-pair emission for entanglement experiments.

Accession Number: WOS:000657003500001

PubMed ID: 33925761

Author Identifiers:

Author        Web of Science ResearcherID        ORCID Number

Li, Shulun                  0000-0001-5894-9436

eISSN: 2079-4991

Full Text: https://www.mdpi.com/2079-4991/11/5/1136