Amorphous silicon is amorphous alloy of Si — H. It is random network of silicon with some hydrogen. And its structure has many unstable bonds as weak bonds of Si—Si and distortion bonds of all kinds. The bonds was broken or was out of shape by light and electrical ageing. It induced increase of defective state that causes character of material going to bad. This drawback will be overcome after microcrystallization of amorphous silicon. It was discovered that a—Si: H was microcrystallized by irradiated of electrons with energy of 0.3-0.5MeV, density of electronic beam of 1.3×10,19,cm,-1,s,-1, and irradiated time of 10—600s. Size of grain is 10—20nm. Thick of microcrystalline lager is 25—250nm.