As the third-generation semiconductors, III-Nitrides exhibits great potentials in the solid-state lighting, display, power device, photovoltaics and so on. The piezoelectric property is the great difference between III-Nitrides and previous semiconductors (Silicon, Germanium, etc.). Prof. Wang pointed it out that the piezo-potential can be used as a gate to tune/control the carrier generation, transport, separation and/or recombination via external strain, and thus tuning the device performances .
This report focuses on piezo-phototronic effects in III-nitrides. Firstly, in the framework of the quantum perturbation theory and constitutive equations, we proposed a self-consistent model to study the piezo-phototronic effects in quantum structure [2,3]. This model matches well with the optical excitation in InGaN/GaN quantum well under the various external stress field. Furthermore, we studied the carrier dynamic process in piezo-phototronic effects with the transit piezo-phototronic model and the time-resolved photoluminescence for the first time. The piezoelectric field was partly “canceled”, which increased the overlap of wavefunctions to decrease the carrier decay time. Thus, the maximum speed of a single chip was increased from 54 MHz up to 117 MHz in a blue LED chip under 0.14% compressive strain. Finally, the piezo-phototronic effect was used to effectively improve the conversion efficiency of InGaN/GaN quantum well and compensated the thermal degradation in high power InGaN/GaN micro-strip LED arrays [4,5]. These researches deepen our understanding on carrier’s excitation and transportation under external strain filed, and exhibits important applications in communication, lighting and energy collections.
1.X. Wang, J. Song, J. Liu, Z. L. Wang, Science 2007, 316 ,102
2.Xin Huang, Chunhua Du, Yongli Zhou, Chunyan Jiang, Xiong Pu, Wei Liu, Weiguo Hu*, Hong Chen*, and Zhong Lin Wang*, ACS Nano 2016 10 (5), 5145-5152
3.Xin Huang, Chunyan Jiang, Chunhua Du, Liang Jing, Mengmeng Liu, Weiguo Hu*, and Zhong Lin Wang*, ACS Nano 10 (12), 11420-11427, 2016
4.Chunyan Jiang, Liang Jing, Xin Huang, Mengmeng Liu, Chunhua Du, Ting Liu, Xiong Pu, Weiguo Hu* and Zhong Lin Wang*, ACS Nano 11 (9), 9405–9412, (2017)
5.Chunhua Du, Liang Jing, Chunyan Jiang, Ting Liu, Xiong Pu, Jiangman Sun, Dabing Li* and Weiguo Hu*, Materials Horizons, DOI 10.1039/C7MH00876G