Thin film cadmium selenide electrodeposited from selenosulphite solution

In a process for electrodepositing a thin layer of cadmium selenide on a suitable electrically conductive substrate comprising immersing a cathode of said substrate in association with an anode in an electrolyte bath having a pH ranging from 5 to 10 and having an aqueous solution of selenosulphite ions and cadmium ions complexed with a complexing agent where said pH range shifts the chemical equilibrium of complexing said cadmium ions towards associated complexed cadmium ions, applying a voltage across said cathode and anode to reduce said selenosulphite ions to produce selenide ions at said cathode of a sufficient concentration which reacts with the complexed cadmium ions to electrodeposit thereby cadmium selenide on said cathode and annealing said electrodeposited cadmium selenide, the improvement comprising the use of nitrilotriacetic acid as said complexing agent.