Effect of structural parameter on field emission properties of semiconducting copper sulphide nanowire films

Films of aligned crystalline copper sulphide $(Cu2S)$ nanowire arrays were grown by using a gas-solid reaction method. By controlling the preparation condition, copper sulphide nanowire arrays with different structural parameters were fabricated. Their field emission characteristics including the total current–applied field characteristics and the distribution of field emission sites are studied and compared using the transparent anode technique. It is found that the turn-on field of the copper sulphide nanowire film relates to the structural parameters of copper sulphide nanowire arrays. Nonlinearity in Fowler–Nordheim plot was observed from film consisting of sparse nanowire arrays with varied field enhancement factor. The physical mechanism accounting for the nonlinearity is discussed.