What Time-Resolved Optical Spectroscopy Can Contribute to Green Technology
Kung-Hsuan Lin1*, Chi-Yuan Yang1, Yu-Ting Chen1
1Institute of Physics, Academia Sinica, Taipei, Taiwan
* Presenter:Kung-Hsuan Lin, email:kunghsuan@gmail.com
Material science is one of important keys to develop green technology. Understanding the underlying mechanisms and properties of materials is crucial to improve the performance of the devices. Efficient energy transfer and management should be one of the core problems. For example, the goal of photovoltaics is to efficiently convert solar energy into direct current electricity. One of the key issues is how to prevent the radiative or nonradiative recombination of electrons and holes after they are generated by photons. Conversely, how electrons and holes could efficiently recombine becomes the key issue to light emitting devices. In addition, the loss of the devices is primarily transferred into heat (phonons). The fundamental issues to energy transfer are thus related to electrons, phonons, photons and their couplings. Dynamic behaviors of their interaction are pivotal to the fundamental properties of materials. In this talk, I will share my partial work how time-resolved optical spectroscopy could contribute to scientific knowledge for green technology. The carrier dynamics of GaN nanorods for light-emitting devices and Mn-doped GaN for photovoltaics will be presented.

[1] C.-Y. Yang, C.-T. Chia, H.-Y. Chen, S. Gwo, and K.-H. Lin, “Ultrafast Carrier Dynamics in GaN nanorods,” Applied Physics Letters, Vol. 105 (21), 212105 (2014).
[2] Y.-T. Chen, C.-Y. Yang, P.-C. Chen, J.-K. Sheu, and K.-H. Lin, “Carrier dynamics of Mn-induced states in GaN thin films,” Scientific Reports, Vol. 7, 5788 (2017).

Keywords: time-resolved, GaN, femtosecond laser, photovoltaics, LED