layer formed on one surface of the substrate one electrode being applied to the substrate and one to the amorphous layer the electrodes formed on the amorphous semiconductor layer consisting of closely spaced interconnected conductive strips which are substantially uniformly arranged over the entire radiation incident surface of the amorphous semiconductor layer whereby the electrostatic capacitance appearing between the electrodes of the detector is significantly reduced without significantly changing the area of the detector that responds to radiation application_number US 15352088 A description in fig1 semiconductor based radiation detector 100 has a substrate 1 of single crystal silicon for example an undoped amorphous silicon layer 2 to which hydrogen has been added is formed on substrate 1 by plasma techniques utilizing monosilane gas for example because of the use of such plasma techniques the specific resistance of the layer 2 is 10 to 100 times greater than that of a layer formed by rf techniques a metal electrode 32 having the shape indicated by the cross hatching in fig1 is then formed on amorphous layer 2 by vacuum evaporation using a metal mask purely by way of example the silicon substrate 1 may have a diameter of 40 mm and the rib electrode 3 is formed on the amorphous layer 2 within a.