Photoinduced Metastable States in Amorphous Organic Polysilanes Studied by the Transient Photocurrent Technique

Ultra-violet-light-induced states in amorphous polymethylphenylsilane have been investigated by a time-of-flight technique for transient photocurrent measurements. It is found that the photo-induced change is reversible below 320 K, while irreversible above 320 K. The finding is attributable to the formation of two photocreated dangling bond states having different metastabilities. It is shown that the experimental results are successfully explained in terms of the configurational-coordinate potential-energy diagram representing the ground-state and two different metastable-dangling-bond-state configurations. Origins of the two metastable dangling bond states are discussed.