Display panel comprising two plates, separated by a gas-filled space partitioned by separating elements forming an array of barrier ribs, and arrays of coplanar sustain electrodes and address electrodes; with each cell subdivided into a trigger zone at each of the intersections of an address electrode with a sustain electrode and into at least one coplanar discharge expansion zone that extends between the trigger zones, the array of barrier ribs is designed so that, in each cell, each coplanar expansion zone has a width that is less than the width of all the trigger zones.By applying a method of driving the sustain discharges in the display panel by matrix triggering, the luminous efficiency is very substantially improved.