Investigations of the electrical properties of electrodeposited CuInSe2 thin films

The electrical properties of as-grown and heat-treated copper indium diselenide (CuInSe₂) thin films electrochemically deposited were measured in the temperature range 30 to about 300 K. In general the films showed variable range hopping conduction mechanism, i.e., σ= (σ₀ T^-1/2) exp[ - (T₀/T)^1/4] with T₀ between 4 × 10² and 6 × 10³ K, at the lowest temperatures, and thermally activated conductivity, i.e., σ = σ₀ exp( - E_a/kT) with E_a between 240 and 80 meV, over the temperature range close to the room temperature. The activation energy, E_a, decreased and the conductivity, σ, increased with the annealing treatment. The data of these annealed films are in agreement with the Meyer-Neldel rule. Grain boundary trapping models were considered in the analysis of the results.