Figures in paper 'Temperature dependence of the band gap of zinc nitride observed in photoluminescence measurements'

The figures included here are related to the publication:
"Temperature dependence of the band gap of zinc nitride observed in photoluminescence measurements".
Appl. Phys. Lett. 111, 122105 (2017); doi: http://dx.doi.org/10.1063/1.4997153

The study reported in this paper was funded by the EPSRC (Fund code EP/M507611/1) and Johnson Matthey PLC. The financial support by these parties is highly appreciated.

Figure 1: XRD pattern of a sample grown at 150 °C. Inset: SEM image of the same sample.

Figure 2: Temperature dependent PL of a sample shortly after growth. The excitation power for these measurements was set to 30 mW.

Figure 3: (a) Temperature dependent PL of the zinc nitride sample after prolonged exposure to ambient. (b) Comparison of the high-energy bands of the same sample before (solid) and after (dashed) prolonged exposure to ambient.

Figure 4: PL spectra of bands A and B at (a) 3.7 and (b) 294 K at different excitation powers. (c) Peak intensities and (d) emission energies of band A at 294 K (●) and bands A (▼) and B (▲) at 3.7 K as a function of excitation power. The spectra in (a) have been normalised at the maximum intensity of band A.

Figure 5: Temperature dependence of (a) relative integrated intensities (I/I0) and (b) the emission energies of band A at an excitation power of 100 mW (●) and bands A (▼) and B (▲) at an excitation power of 1 mW.