Large red-shift of luminescence from BaCN2:Eu2+ red phosphor under high pressure

We report a new material, BaCN2:Eu2+ for a very sensitive optical pressure sensor, 50 times more sensitive than ruby. Photoluminescence spectra of the BaCN2:Eu2+ phosphor was measured under hydrostatic pressures from ambient pressure to 5.34 GPa at room temperature. The peak wavelength of the luminescence was drastically red-shifted at a rate of 19 nm GPa(-1), which is approximately 50 times larger than that of the ruby, most commonly used as a pressure sensor in the high-pressure experiments. This large shift of the luminescence wavelength is suitable for application in optical pressure sensors for the high-pressure experiments without a high-resolution monochromator.