The invention provides, amongst others for application in a lighting unit, a
phosphor having the formula M1−x−y−zZzAaBbCcDdEeN4−nOn:ESxREy (I), with M=selected from the group consisting of Ca, Sr, and Ba; Z=selected from the group consisting of monovalent Na, K, and Rb; A=selected from the group consisting of
divalent Mg, Mn, Zn, and Cd; B=selected from the group consisting of trivalent B, Al and Ga; C=selected from the group consisting of tetravalent Si, Ge, Ti, and Hf; D=selected from the group consisting of monovalent Li, and Cu; E=selected for the group consisting of P, V, Nb, and Ta; ES=selected from the group consisting of
divalent Eu, Sm and Yb; RE=selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; 0≦x≦0.2; 0≦y≦0.2; 0<x+y≦0.4; 0≦z<1; 0≦n≦0.5; 0≦a≦4 (such as 2≦a≦3); 0≦b≦4; 0≦c≦4; 0≦d≦4; 0≦e≦4; a+b+c+d+e=4; and 2a+3b+4c+d+5e=10−y−n+z.