Fig 1.
The cross-sectional TEM image for GaN/InGaN multiple quantum well heterostructures.
In the MQWs heterostructure, the thicknesses of the InGaN well and GaN barrier were chosen to be 2 nm and 11 nm for the heterostructure samples.
Fig 2.
The electroluminescence (EL) and photoluminescence (PL) spectra of GaN/InGaN heterostructures at an ambient temperature of 300 K.
The EL spectrum was measured under a direct injection current level of 20 mA.
Fig 3.
The current-voltage characteristics of GaN/InGaN heterosystems with increasing InN molar fractions (S1 to S3) measured at an injection current level of 20 mA.
Fig 4.
(a) The emission peak energy from EL and PL measurements for GaN/InGaN blue MQB heterostrucutres at different temperatures. (b, c) The thermal-related FWHM from EL and PL measurement experiments can be used to study the thermal effects of GaN/InGaN heterstructures, of the photon-electron interaction with the lattice.
Fig 5.
The EL and PL junction temperatures obtained from the forward voltage and wavelength shift techniques and the EL and PL carrier temperatures estimated from the high-energy band tails of the InGaN luminescence spectra for GaN/InGaN blue MQB heterostrucutres.
Fig 6.
The EL and PL Debye temperature extracted from the observations of the FWHM and red-shift in the emission peak as a function of tuning of the In composition in InGaN interlayers.
The inset shows, the dependence of the observed EL/PL related quantum efficiency (QE) on the variation of the indium composition for S1 to S3.
Table 1.
The values of normalized quantum efficiency, Debye temperature, junction/carrier temperature for S1 to S3; The experiment data which published on previous reports of electroluminescence measurement with different kind of heterostructure configuration to estimated thermodynamic intensive parameter.