Method for the preparation of group IB-IIIA-VIA quaternary or higher alloy semiconductor films

A method for producing a group IB-IIIA-VIA quaternary alloy semiconductor film, the method comprising the steps of:

• (i) providing a metal film comprising a mixture of at least one group IB element a first group IIIA element, the first group IIIA element hereinafter being referred to as IIIA1, and a second group IIIA element, the second group IIIA element hereinafter being referred to as IIIA2;
• (ii) heat treating the metal film in the presence of a source of a first group VIA element, said first group VIA element being hereinafter referred to as VIA1 under such conditions that the reaction between the group VIA1 element and the metals of the mixture of the metal film is incomplete and a first film is formed comprising a mixture of at least one binary alloy selected from the group consisting of a group IB-VIA1 alloy and a group IIIA-VIA1 alloy;
• and at least one group IB-IIIA-VIA1 ternary alloy, wherein the mixture is a stable mixture such that the molar ratio of all the group IB-VIA1 and/or group IIIA-VIA1 alloys to the at least one group IB-IIIA-VIA1 ternary alloy remains substantially constant, and
• (iv) heat treating the first film of step (ii) to form a group IB-IIIA-VIA quaternary alloy semiconductor film.

A method for producing a group IB-IIIA-VIA quaternary alloy semiconductor film, the method comprising:

• step (i):
• providing a metal film including a mixture of at least one group IB element and a group IIIA element;
• step (ii):
• heat treating the metal film of step (i) in the presence of a source of VIA1 under such conditions that the reaction between the group VIA1 element and the metals of the mixture of the metal film is incomplete and a first film is formed comprising a mixture of binary alloys selected from the group consisting of a group IB-VIA1 alloy, a group IIIA-VIA1, and a ternary alloy being a group IB-IIIA-VIA1 alloy;
• and
• step (iv) comprises heat treating the first film of step (ii) in the presence of a source of VIA2 so-as to form a group IB-IIIA-VIA1-VIA2 quaternary alloy semiconductor film.