Silicon thin film transistors and solar cells on plastic substrates

1 . A method for fabricating a silicon-containing film which comprises depositing a thin film of amorphous silicon on a substrate by a plasma-enhanced chemical vapor deposition process in a reaction chamber and converting at least a portion of the amorphous silicon to crystalline silicon by irradiating the film with pulsed laser energy in a hydrogen-containing atmosphere.

2 . The method of claim 1 wherein hydrogen is present in the hydrogen-containing atmosphere at a partial pressure of 1 to 600 Torr.

3 . The method of claim 1 wherein hydrogen gas is introduced into the reaction chamber to provide the hydrogen-containing atmosphere.

4 . The method of claim 1 wherein a hydrogen plasma is generated external to the reaction chamber and introduced into the reaction chamber to provide the hydrogen-containing atmosphere.

5 . The method of claim 1 wherein the substrate comprises material selected from the group consisting of polyethyleneterephthalate, ethylenechlorotrifluoroethylene, ethylenetetrafluoroethylene, polyethersulfone, polytetrafluoroethylene, high-density polyethylene, polyarylate, polycarbonate, and Mylar®.

6 . The method of claim 1 wherein the plasma-enhanced chemical vapor deposition process utilizes one or more gases selected from the group consisting of silane, disilane, hydrogen, and argon.

7 . The method of claim 1 wherein the average temperature of the substrate during plasma-enhanced chemical vapor deposition is less than 100° C.

8 . The method of claim 1 wherein the average temperature of the substrate while irradiating the film with pulsed laser energy is less than 100° C.

9 . The method of claim 1 wherein the plasma-enhanced chemical vapor deposition process utilizes diborane and one or more gases selected from the group consisting of silane, disilane, hydrogen, and argon to deposit boron-doped amorphous silicon.

10 . The method of claim 1 wherein the plasma-enhanced chemical vapor deposition-process utilizes phosphene and one or more gases selected from the group consisting of silane, disilane, hydrogen, and argon to deposit phosphorous-doped amorphous silicon.

11 . The method of claim 1 which further comprises depositing nickel on the thin film of amorphous silicon prior to irradiating the film with pulsed laser energy.

12 . A composite article which comprises

(a) a substrate; and

(b) a silicon-containing film applied to the substrate by a process which comprises depositing a thin film of amorphous silicon on a substrate by a plasma-enhanced chemical vapor deposition process in a reaction chamber and converting at least a portion of the amorphous silicon to crystalline silicon by irradiating the film with pulsed laser energy in a hydrogen-containing atmosphere.

13 . The composite article of claim 12 wherein the substrate comprises material selected from the group consisting of polyethyleneterephthalate, ethylenechlorotrifluoroethylene, ethylenetetrafluoroethylene, polyethersulfone, polytetrafluoroethylene, high-density polyethylene, polyarylate, polycarbonate, and Mylar®.

14 . The composite article of claim 12 wherein the silicon-containing film further comprises phosphorous or boron.

15 . A method of fabricating a multi-layer silicon solar cell structure comprising

(a) depositing a first thin film comprising phosphorous-doped amorphous silicon on a substrate by a plasma-enhanced chemical vapor deposition process;

(b) depositing a second thin film comprising undoped amorphous silicon on at least a portion of the first film by a plasma-enhanced chemical vapor deposition process;

(c) depositing a third thin film comprising boron-doped amorphous silicon on at least a portion of the second film by a plasma-enhanced chemical vapor deposition process to form the multi-layer silicon solar cell structure; and

(d) converting at least a portion of the amorphous silicon in the multi-layer silicon solar cell structure to crystalline silicon by irradiating the film with pulsed laser energy in a hydrogen-containing atmosphere.

16 . A composite article comprising

(a) a substrate; and

(b) a multi-layer silicon solar cell structure deposited on the substrate by a process comprising

(1) depositing a first thin film comprising phosphorous-doped amorphous silicon on a substrate by a plasma-enhanced chemical vapor deposition process;

(2) depositing a second thin film comprising undoped-amorphous silicon on at least a portion of the first film by a plasma-enhanced chemical vapor deposition process;

(3) depositing a third thin film comprising boron-doped amorphous silicon on at least a portion of the second film by a plasma-enhanced chemical vapor deposition process to form the multi-layer silicon solar cell structure; and

(4) converting at least a portion of the amorphous silicon in the multi-layer silicon solar cell structure to crystalline silicon by irradiating the film with pulsed laser energy in a hydrogen-containing atmosphere.