Email: a.bettiol@nus.edu.sg
Office: S12-03-13
Tel: +65 6516 4138
Current Research
- Nuclear microscopy – Super-resolution imaging of whole biological cells. Development of novel imaging modalities using MeV ion beams. Spatial and temporal imaging of fluorescent emitters and nano-particle uptake in cells. Imaging semiconductors and devices using single ion techniques.
- Ion beam modification of materials – Modifying optical, electrical and magnetic properties of materials including bulk materials, semiconductors, non-linear optical materials and 2D materials. Colour centre engineering and deterministic ion implantation and doping of materials for quantum applications.
- Radiobiology – Radiation effects in biological cells. Targeted irradiation of cellular and sub-cellular structures. Development of single proton dosimetry techniques. Diamond-based radiation detection and dosimetry. Novel scintillators for radiation detection and measurement.
Color centers are a type of fluorescent atom-size defect in a crystal. They have recently shown great promises as single photon emitters for quantum technologies such as quantum communication and optical sensing. Energetic light ions at MeV energy are highly efficient at creating point defects or isolated lattice vacancies, which can be a powerful tool for color center engineering in wide bandgap materials. Here we present fabrication of diamond color centers by MeV helium ion implantation and application of the color centers for magnetic field sensing. One of the most promising color centers in diamond is negatively charged silicon-vacancy (SiV¯) centre for its high efficiency in producing indistinguishable photons. Implanting helium ions (1.6 MeV) at the nucleation surface of a polycrystalline diamond film enables a layer of bright and dense SiV¯ in the surface vicinity.
Fabrication process and PL mapping of the SiV¯ centers in the diamond film.
Formation process of the SiV¯ centers
PL map of patterned SiV¯ centers on the nucleation surface. Fluence was varied from 5E14 cm-2 to 5E15 cm-2. Scale bar: 10 µm.
Selected Publications
- Zhaohong Mi, Ce-Belle Chen, Hong Qi Tan, Yanxin Dou, Chengyuan Yang, Shuvan Prashant Turaga, Minqin Ren, Saumitra K. Vajandar, Gin Hao Yuen, Thomas Osipowicz, Frank Watt, and Andrew A. Bettiol. Quantifying nanodiamonds biodistribution in whole cells with correlative iononanoscopy. Nature Communications, 12 (1):4657 (2021)
- Huining Jin and Andrew A. Bettiol. Influence of thermal annealing on the properties of proton implanted diamond waveguides. Carbon, 171:560–567, JAN 2021.
- Prakash Pitchappa, Abhishek Kumar, Haidong Liang, Saurav Prakash, Nan Wang, Andrew A. Bettiol, Thirumalai Venkatesan, Chengkuo Lee, and Ranjan Singh. Frequency-agile temporal terahertz metamaterials. Advanced Optical Materials, 8(12):2000101, JUN 2020.
- Xiao Zeng, Sudheer Kumar Vanga, Eng Tuan Poh, Yi Shi, Chorng Haur Sow, Andrew Anthony Bettiol, and Xiaogang Liu. Photolithographic fabrication of upconversion barcodes for multiplexed molecular detection. Advanced Optical Materials, 8(22):2001168, NOV 2020.
- Shuvan Prashant Turaga, Huining Jin, Ee Jin Teo, and Andrew A. Bettiol. Cross-sectional hyperspectral imaging of proton implanted diamond. Applied Physics Letters, 115(2):021904, JUL 2019.
- Chengyuan Yang, Shuvan Prashant Turaga, Andrew A. Bettiol, Pranesh Balamuniappan, Michel Bosman, Hui Ru Tan, Jing Hua Teng, and Ee Jin Teo. Textured v-pit green light emitting diode as a wavelength-selective photodetector for fast phosphor-based white light modulation. ACS Photonics, 4(3):443–448, FEB 2017.
- Andrew A. Bettiol, Zhaohong Mi, and Frank Watt. High-resolution fast ion microscopy of single whole biological cells. Applied Physics Reviews, 3(4):041102, DEC 2016.
- Zhaohong Mi, Yuhai Zhang, Sudheer Kumar Vanga, Ce-Belle Chen, Hong Qi Tan, Frank Watt, Xiaogang Liu and Andrew A. Bettiol, Subwavelength imaging through ion-beam-induced upconversion, Nature Communications 6, 8832 (2015)
- Sher-Yi Chiam, Ranjan Singh, Carsten Rockstuhl,Weili Zhang, Falk Lederer and A.A. Bettiol, Analogue of electromagnetically induced transparency in a terahertz metamaterial, Physical Review B 80 (2009) 153103
- C. Udalagama, A. A. Bettiol and F. Watt, Stocastic spatial energy deposition profiles for MeV protons and keV electrons, Physical Review B 80 (2009) 224107