Plenary Session 1 (9:00 ~ 10:20, Nov. 13, 2023)

Chair: Professor Kui Yao (Institute of Materials Research and Engineering, Singapore)

 

Plenary Talk – 1

 

Piezo-phototronics of the third generation semiconductors

 

Zhong Lin WANG

 

Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083.

Georgia Institute of Technology, USA

 

The first generation semiconductors (Si, Ge) and the second generation semiconductors (GaAs) have a common characteristic: their crystal structures are cubic, so that they have little piezoelectric effect. However, for the third generation semiconductors, such as GaN. SiC and ZnO, they have the hexagonal crystal structure, which means that they have unique piezoelectric effect. Due to the polarization of ions in a crystal that has non-central symmetry once subject to a mechanical strain, a piezoelectric potential (piezopotential) is created in the crystal. Electronics fabricated by using inner-crystal piezopotential as a “gate” voltage to tune/control the charge transport behavior is named piezotronics, with applications in strain/force/pressure triggered/controlled electronic devices, sensors and logic units. Using the piezoelectric polarization charges at the pn  junction to control charge carrier separation or combination process in optoelectronics is called the piezo-phototronic effect. This talk will focus on how to use piezo-phototronic effect to tune the efficiency of LED lighting and solar cells. 

 

[1]   W.Z. Wu, X.N. Wen, Z.L. Wang “Pixel-addressable matrix of vertical-nanowire piezotronic transistors for active/adaptive tactile imaging”, Science, 340 (2013) 952-957.

[2]   C.F. Pan, L. Dong, G. Zhu, S. Niu, R.M. Yu, Q. Yang, Y. Liu, Z.L. Wang* “Micrometer-resolution electroluminescence parallel-imaging of pressure distribution using piezoelectric nanowire-LED array”, Nature Photonics, 7 (2013) 752-758.

[3]    Q. Yang, W.H. Wang, S. Xu and Z.L. Wang^* “Enhancing light emission of ZnO microwire-based diodes by piezo-phototronic effect”, Nano Letters, 11 (2011) 4012–4017.

[4]  W.Z. Wu and Z.L. Wang “Piezotronics and piezo-phototronics for smart adaptive electronics and optoelectronics”, Nature Review Materials, 1 (2016) 16031 doi:10.1038/natrevmats.2016.31.

[5]   “Piezotronics and Piezo-phototronics with the Third-generation Semiconductors”, MRS Bulletin, 43 (2018) 922-926; https://doi.org/10.1557/mrs.2018.263

[6] Caofeng Pan^*, Junyi Zhai^* and Zhong Lin Wang^* “Piezotronics and piezo-phototronics of third generation semiconductor nanowires” (Review), Chemical Review, (2019) 119, 15, 9303-9359; DOI:10.1021/acs.chemrev.8b00599

 

 

 

About speaker:

 

Professor Zhong Lin Wang is the Regents' Professor and Hightower Chair at Georgia Institute of Technology, Director of the Beijing Institute of Nanoenergy and Nanosystems. Prof. Wang pioneered the nanogenerators field for distributed energy, self-powered sensors and large-scale blue energy. He coined the fields of piezotronics and piezo-phototronics for the third generation semiconductors. Among 100,000 scientists across all fields worldwide, Prof. Wang is ranked #3 in career scientific impact, #1 in Nanoscience, and #1 in Materials Science based on citations and big data. His google scholar citation is over 367,000 with an h-index of over 292.

Prof. Wang has received the Celsius Lecture Laureate, Uppsala University, Sweden (2020); The Albert Einstein World Award of Science (2019); Diels-Planck lecture award (2019); ENI award in Energy Frontiers (2018); The James C. McGroddy Prize in New Materials from American Physical Society (2014); and MRS Medal from Materials Research Soci. (2011). Prof. Wang was elected as a fellow of the US National Academy of Inventors in 2022, foreign member of the Chinese Academy of Sciences in 2009, member of European Academy of Sciences in 2002, academician of Academia of Sinica 2018, International fellow of Canadian Academy of Engineering 2019. Porf. Wang is the founding editor and chief editor of an international journal Nano Energy, which now has an impact factor of 19.0.