Provided is a field shaping multi-well photomultiplier and method for fabrication thereof. The photomultiplier includes a field-shaping multi-well avalanche detector, including a lower insulator, an a-Se photoconductive layer and an upper insulator. The a-Se photoconductive layer is positioned between the lower insulator and the upper insulator. A light interaction region, an avalanche region, and a collection region are provided along a length of the photomultiplier, and the light interaction region and the collection region are positioned on opposite sides of the avalanche region.