The photoluminescence of a novel yellow emitting phosphor K2ZrSi2O7:Bi3+ that contains no rare earth ions was investigated. This phosphor was further evaluated as a color converter for white LEDs. The results indicate that K2ZrSi2O7:Bi3+ has strong absorption in 300-400 nm region due to the S-1(0) (->) P-3(1) transition of Bi3+. Upon excitation into the P-3(1) level of Bi3+, K2ZrSi2O7:Bi3+ gives bright and broad yellow emission (FWHM similar to 125 nm) peaking at 560 nm. Except for intensity, the spectral position and shape of the yellow emission band are the same for different concentrations of Bi3+ incorporated K2ZrSi2O7; Both the emission spectra measured at liquid nitrogen temperature (77 K) and room temperature have no splitting and they can be well fitted by a single Gaussian profile; time resolved luminescence spectra reveal that the shape of the emission spectra remain unchanged with increasing delay time. These results indicate only one type of Bi3+ center exists in K2ZrSi2O7. Accompanied by a decrease of emission intensity, the emission of Bi3+ is blue-shifted upon heating (lambda(max) = 560 nm at T = 25 degrees C vs. lambda(max) = 550 nm at T = 250 degrees C), which is ascribed to the thermally active phonon-assisted tunneling from the excited states of lower-energy emission band to those of higher-energy emission band. The white light has been reached using K2ZrSi2O7:Bi3+ as a yellow emitting phosphor. (C) 2016 Elsevier B.V. All rights reserved.