2020, Sun, Xiaoxiao, Wang, Ping, Wang, Tao, Chen, Ling, Chen, Zhaoying, Gao, Kang, Aoki, Tomoyuki, Li, Mo, Zhang, Jian, Schulz, Tobias, Albrecht, Martin, Ge, Weikun, Arakawa, Yasuhiko, Shen, Bo, Holmes, Mark, Wang, Xinqiang

We identify and characterize a novel type of quantum emitter formed from InGaN monolayer islands grown using molecular beam epitaxy and further isolated via the fabrication of an array of nanopillar structures. Detailed optical analysis of the characteristic emission spectrum from the monolayer islands is performed, and the main transmission is shown to act as a bright, stable, and fast single-photon emitter with a wavelength of ~400 nm. © 2020, The Author(s).

2021, Yang, Zhuo, Li, Mo, East, Andrew R., Zude-Sasse, Manuela

Kiwifruit chilling injury (CI) damage occurs after long-term exposure to low temperature. A non-destructive approach to detect CI injury was tested in the present study, using a laser backscattering image (LBI) technique calibrated with 56 liquid phantoms for providing absorption coefficient (µa) and reduced scattering coefficient (µs’). Calibration of LBI resulted in a true-positive (TP) classification of 91.5% and 65.6% of predicted µs’ and µa, respectively. The optical properties of ‘SunGold™’and ‘Hayward’ kiwifruit were analysed at 520 nm with a two-step protocol capturing pre-classification according to the LBI parameters used in the calibration and estimation with the Farrell equation. Severely injured kiwifruit showed white corky tissue and water soaking, reduced soluble solids content and firmness measured destructively. Non-destructive classification results for ‘SunGold™’ showed a high percentage of TP for severe CI of 92% and 75% using LBI parameters directly and predicted µa and µs’ after pre-classification, respectively. The classification accuracy for severe CI ‘Hayward’ kiwifruit with LBI parameter was low (58%) and with µa and µs’ decreased further (35%), which was assumed to be due to interference caused by the long trichomes on the fruit surface.

2017, Ma, Dingyu, Rong, Xin, Zheng, Xiantong, Wang, Weiying, Wang, Ping, Schulz, Tobias, Albrecht, Martin, Metzner, Sebastian, Müller, Mathias, August, Olga, Bertram, Frank, Christen, Jürgen, Jin, Peng, Li, Mo, Zhang, Jian, Yang, Xuelin, Xu, Fujun, Qin, Zhixin, Ge, Weikun, Shen, Bo, Wang, Xinqiang

We investigate the emission from confined excitons in the structure of a single-monolayer-thick quasi-two-dimensional (quasi-2D) Inx Ga1-x N layer inserted in GaN matrix. This quasi-2D InGaN layer was successfully achieved by molecular beam epitaxy (MBE), and an excellent in-plane uniformity in this layer was confirmed by cathodoluminescence mapping study. The carrier dynamics have also been investigated by time-resolved and excitation-power-dependent photoluminescence, proving that the recombination occurs via confined excitons within the ultrathin quasi-2D InGaN layer even at high temperature up to ∼220 K due to the enhanced exciton binding energy. This work indicates that such structure affords an interesting opportunity for developing high-performance photonic devices.