Efficiency enhancement of InGaN/GaN multiple quantum wells with graphene layer
- 298 Downloads
In this work, a novel hybrid graphene/InGaN-based multiple quantum wells (MQWs) structure has been fabricated. Compared to the sample conventional structure (CS), the utilization of graphene transferred on top GaN layer significantly enhances the internal quantum efficiency and relatively photoluminescence intensity. Furthermore, the excitons in the MQWs of sample hybrid structure (HS) have a shorter decay lifetime of 3.4 ns than that of 6.7 ns for sample CS. These results are probably attributed to the free carriers in the graphene layer, which can screen the piezoelectric field in the active region and thus present a free quantum-confined Stark effect-like behavior. Our work demonstrates that the graphene on the top GaN layer can effectively increase the recombination rate in sample HS, which may further improve LEDs’ performance.
KeywordsGraphene Layer Polarization Field Excitation Power Internal Quantum Efficiency Decay Lifetime
This work was supported by National Basic Research Program of China (Grant Nos. 2011CB925604) and National Nature Science Foundation (Grant Nos. 11204360, 61210014 and 11374340).
- 5.P.C. Tsai, Y.K. Su, W.R. Chen, C.Y. Huang, Jpn. J. Appl. Phys. 49, 04DG07 (2010)Google Scholar