Figure 7

The 14N resonance frequency of CH3NH3PbBr3 single crystal as a function of temperature (inset: 14N NMR spectrum at tetragonal phase of 225 K and cubic phase of 270 K).

The 14N resonance frequency of CH3NH3PbBr3 single crystal as a function of temperature (inset: 14N NMR spectrum at tetragonal phase of 225 K and cubic phase of 270 K).