The paper deals with photoconductivity and absorption in aSi specimens, prepared mainly by the decomposition of silane in a glow discharge. Substrate temperatures, T d, between 300 K and 650 K were used during deposition. The normalised photoresponse was measured at room temperature as a function of photon energy and T d in a spectral range from 0.5 eV to 3 eV. The absorption coefficient was determined for evaporated, sputtered and glow discharge specimens. The main features of the results are in agreement with conclusions drawn from previous electrical transport and field effect measurements and can be interpreted on the basis of the proposed model for the localised state distribution. It is confirmed that ϵ c−ϵ v is 1.5 to 1.6 eV, and that there is a local density of state maximum at about 1.2 eV below ϵ c. At room temperature the steady photocurrent is carried predominantly by electrons in states above ϵ c, whether excitation is from localized or extended states. Specimens prepared at T d > 500 K are highly photosensitive, with electron recombination lifetimes, τ, of up to 10 −5s. Rise and decay times of the signal lie in the millisecond range. For T d < 500 K there is a drastic decrease in τ, which falls to 10 −11 s at T d ⋍ 300 K and is even less for evaporated specimens. These results are discussed in some detail.