Bright Single-Photon Emitters with a CdSe Quantum Dot and Multimode Tapered Nanoantenna for the Visible Spectral Range

• Main Authors: Maxim Rakhlin, Sergey Sorokin, Dmitrii Kazanov, Irina Sedova, Tatiana Shubina, Sergey Ivanov, Vladimir Mikhailovskii, Alexey Toropov
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Nanomaterials
• Subjects: quantum dots; single-photon emission; CdSe; MBE; nanoantenna
• Online Access: https://www.mdpi.com/2079-4991/11/4/916

We report on single photon emitters for the green-yellow spectral range, which comprise a CdSe/ZnSe quantum dot placed inside a semiconductor tapered nanocolumn acting as a multimode nanoantenna. Despite the presence of many optical modes inside, such a nanoantenna is able to collect the quantum dot radiation and ensure its effective output. We demonstrate periodic arrays of such emitters, which are fabricated by focused ion beam etching from a II-VI/III-V heterostructure grown using molecular beam epitaxy. With non-resonant optical pumping, the average count rate of emitted single photons exceeds 5 MHz with the second-order correlation function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>g</mi><mrow><mo>(</mo><mn>2</mn><mo>)</mo></mrow></msup></semantics></math></inline-formula>(0) = 0.25 at 220 K. Such single photon emitters are promising for secure free space optical communication lines.