This invention relates to a method to manufacture a chip to detect the direct conversion of X-rays. It also relates to a direct conversion detector for X-rays using such a chip and dental radiology equipment using at least one such detector. The method to manufacture the wafer comprises a step for applying pressure (3, 4, 4 a) to a powdered polycrystalline semiconductor material and a step for heating (5-9) during a set time period. It comprises a preliminary step for providing an impurity level of at least 0.2% in the polycrystalline semiconductor material.