Date/Time: 04-03-2018 - Tuesday - 05:00 PM - 07:00 PM
Parth Vashishtha1 2 Jonathan Halpert3 1 2

1, Victoria University of Wellington, Wellington, , New Zealand
2, MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, , New Zealand
3, Hong Kong University of Science and Technology (HKUST), Hong Kong, , Hong Kong

Inorganic perovskite semiconductor quantum dots have proven to be useful material for electronic devices, such as light emitting devices (LEDs), solar cells, and radiation detectors due to their tuneable optical properties, thin linewidth emission spectra, wide bandgap, and high absorption coefficient.1-4 Recently, organic-metal halide perovskite materials have attracted extensive research due to their unique optical properties and solution-based processing techniques.5-6 In this work, for the first time, we synthesize high band gap monodispersed novel perovskite halide nanocrystals and nanowires with tuneable optical properties by colloidal route method via mixed metal alloying with Group 13 metals in the ABX3 perovskite and A3BX5 crystal structures. The size (15-30 nm) of these nanocrystals can be tuned by the reaction condition. Halide composition can also be varied to achieve the desired optical properties. Finally, we successfully controlled the shape of these nanocrystals and synthesize nanowires with some phase change in the crystal structure. We present the advantage of wide bandgap perovskite semiconductors, showed its photoconductivity and time response which proves the potential application in photodetectors, piezoelectric applications and X-ray detection.

1. Yang, Yixing, et al. "High-efficiency light-emitting devices based on quantum dots with tailored nanostructures." Nature Photonics 9.4 (2015): 259-266.
2. Anikeeva, Polina O., et al. "Quantum dot light-emitting devices with electroluminescence tunable over the entire visible spectrum." Nano letters 9.7 (2009): 2532-2536.
3. Chuang, Chia-Hao M., et al. "Improved performance and stability in quantum dot solar cells through band alignment engineering." Nature materials 13.8 (2014): 796-801.
4. Farzaneh, Azadeh, and Mohammad Reza Abdi. "CsI nanocrystal doped with Eu 2+ ions for radiation detection." Journal of Luminescence(2017).
5. Deschler, Felix, et al. "High Photoluminescence Efficiency and Optically Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors." (2014).
6. Yakunin, Sergii, et al. "Detection of X-ray photons by solution-processed lead halide perovskites." Nature photonics 9.7 (2015): 444-449.

Meeting Program

5:00 PM–7:00 PM Apr 3, 2018

PCC North, 300 Level, Exhibit Hall C-E