Device and method for generating a plasma jet
A device for generating a plasma jet is disclosed. A nozzle of the device comprises an inner, middle and outer channel surrounding each other and electrically insulated from each other. The device is configured for flowing through the inner, middle and outer channel respectively a first ignitable gas, a monomer precursor and a second ignitable gas towards their respective exit openings. A high voltage electrode is arranged in the inner channel for generating a plasma from the first ignitable gas. The nozzle further comprises a nozzle cap enclosing a mixing volume after the exit openings of the inner, middle and outer channel. The nozzle cap is provided with an exit opening after the mixing volume, which exit opening is smaller than the exit opening of the outer channel.
1. A device for generating a plasma jet, wherein a nozzle of the device comprises:
an inner channel, wherein the device is configured for flowing a first ignitable gas through the inner channel towards an exit opening of the inner channel, wherein a high voltage electrode is arranged in the inner channel for generating a plasma from the first ignitable gas flowing in the inner channel;
a middle channel, wherein the middle channel surrounds the inner channel, wherein the middle channel is electrically insulated from the inner channel, wherein the device is configured for flowing a monomer precursor through the middle channel towards an exit opening of the middle channel;
an outer channel, wherein the outer channel surrounds the middle channel, wherein the outer channel is electrically insulated from the middle channel, wherein the device is configured for flowing a second ignitable gas through the outer channel towards an exit opening of the outer channel; and
a nozzle cap, wherein the nozzle cap encloses a mixing volume located after the exit openings of the inner channel, the middle channel and the outer channel, and wherein the nozzle cap is provided with an exit opening after the mixing volume, wherein the exit opening of the nozzle cap is smaller than the exit opening of the outer channel.
2. The device according to claim 1 , wherein the mixing volume is adapted for mixing the plasma of the first ignitable gas from the inner channel, the monomer precursor from the middle channel and the second ignitable gas from the outer channel.
3. The device according to claim 1 , wherein the mixing volume is located within the nozzle cap.
4. The device according to claim 1 , wherein an inner wall of the nozzle cap encloses the mixing volume.
5. The device according to claim 1 , wherein the mixing volume is located directly after the exit openings of the inner channel, the middle channel and the outer channel.
6. The device according to claim 1 , wherein the exit opening of the nozzle cap is located directly after the mixing volume.
7. The device according to claim 1 , wherein the mixing volume extends from the exit openings of the inner channel, the middle channel and the outer channel to the exit opening of the nozzle cap.
8. The device according to claim 1 , wherein the exit opening of the nozzle cap is smaller than or equal to the exit opening of the middle channel.
9. The device according to claim 1 , wherein an inner wall of the nozzle cap is shaped for gradually guiding a flow of the second ignitable gas in the mixing volume from the exit opening of the outer channel towards the exit opening of the nozzle cap.
10. The device according to claim 9 , wherein the inner wall of the nozzle cap is funnel shaped.
11. The device according to claim 1 , wherein the nozzle cap is arranged for being removably connected to the nozzle of the device.
12. The device according to claim 1 , wherein the device is configured for flowing the first ignitable gas at a predetermined first flow rate through the inner channel towards the exit opening of the inner channel, wherein a first flow rate is at least 0.1 slm, preferably at least 0.2 slm, more preferably at least 0.3 slm, even more preferably at least 0.4 slm, and/or at most 0.9 slm, preferably at most 0.8 slm, more preferably at most 0.7 slm, even more preferably at most 0.6 slm, and most preferably 0.5 slm.
13. The device according to claim 1 , wherein the device is configured for flowing the monomer precursor at a predetermined second flow rate through the middle channel towards the exit opening of the middle channel, wherein a second flow rate is at least 50 sccm, preferably at least 100 sccm, more preferably at least 150 sccm, even more preferably at least 200 sccm, and/or at most 650 sccm, preferably at most 550 sccm, more preferably at most 450 sccm, even more preferably at most 350 sccm, and most preferably 250 sccm.
14. The device according to claim 1 , wherein the device is configured for flowing a carbon based monomer precursor through the middle channel towards the exit opening of the middle channel.
15. The device according to claim 1 , wherein the device is configured for flowing the second ignitable gas at a predetermined third flow rate through the outer channel towards the exit opening of the outer channel, wherein a third flow rate is at least 0.2 slm, preferably at least 0.4 slm, more preferably at least 0.6 slm, even more preferably at least 0.8 slm, and/or at most 5 slm, preferably at most 4 slm, more preferably at most 3 slm, even more preferably at most 2 slm, and most preferably 1 slm.
16. The device according to claim 1 , wherein the exit opening of the nozzle cap has a diameter of at least 0.5 mm, preferably at least 1 mm, more preferably at least 1.5 mm, even more preferably at least 2 mm, and/or at most 9 mm, preferably at most 8 mm, more preferably at most 7 mm, even more preferably at most 6 mm.
17. The device according to claim 1 , wherein the exit opening of the nozzle cap is adjustable in size.
18. A method for generating a plasma jet, wherein the method comprises the steps of:
flowing a first ignitable gas through an inner channel towards an exit opening of the inner channel, and generating a plasma from the first ignitable gas flowing in the inner channel by a high voltage electrode arranged in the inner channel;
flowing a monomer precursor through a middle channel towards an exit opening of the middle channel, wherein the middle channel surrounds the inner channel, and wherein the middle channel is electrically insulated from the inner channel; and
flowing a second ignitable gas through an outer channel towards an exit opening of the outer channel, wherein the outer channel surrounds the middle channel, wherein the outer channel is electrically insulated from the middle channel;
mixing the plasma of the first ignitable gas, the monomer precursor and the second ignitable gas in a mixing volume of a nozzle cap located after the exit openings of the inner channel, the middle channel and the outer channel; and
ejecting the mixture of the plasma of the first ignitable gas, the monomer precursor and the second ignitable gas in the mixing volume out of an exit opening of the nozzle cap located after the mixing volume, wherein the exit opening of the nozzle cap is smaller than the exit opening of the outer channel.
19. The method according to claim 18 , wherein the first ignitable gas is flowed at a predetermined first flow rate through the inner channel towards the exit opening of the inner channel, wherein a first flow rate is at least 0.1 slm, preferably at least 0.2 slm, more preferably at least 0.3 slm, even more preferably at least 0.4 slm, and/or at most 0.9 slm, preferably at most 0.8 slm, more preferably at most 0.7 slm, even more preferably at most 0.6 slm, and most preferably 0.5 slm.
20. The method according to claim 18 , wherein the monomer precursor is flowed at a predetermined second flow rate through the middle channel towards the exit opening of the middle channel, wherein a second flow rate is at least 50 sccm, preferably at least 100 sccm, more preferably at least 150 sccm, even more preferably at least 200 sccm, and/or at most 650 sccm, preferably at most 550 sccm, more preferably at most 450 sccm, even more preferably at most 350 sccm, and most preferably 250 sccm.
21. The method according to claim 18 , wherein the second ignitable gas is flowed at a predetermined third flow rate through the outer channel towards the exit opening of the outer channel, wherein a third flow rate is at least 0.2 slm, preferably at least 0.4 slm, more preferably at least 0.6 slm, even more preferably at least 0.8 slm, and/or at most 5 slm, preferably at most 4 slm, more preferably at most 3 slm, even more preferably at most 2 slm, and most preferably 1 slm.
22. The method according to claim 18 , wherein the method is performed by a device for generating a plasma jet, wherein a nozzle of the device comprises:
an inner channel, wherein the device is configured for flowing a first ignitable gas through the inner channel towards an exit opening of the inner channel, wherein a high voltage electrode is arranged in the inner channel for generating a plasma from the first ignitable gas flowing in the inner channel;
a middle channel, wherein the middle channel surrounds the inner channel, wherein the middle channel is electrically insulated from the inner channel, wherein the device is configured for flowing a monomer precursor through the middle channel towards an exit opening of the middle channel;
an outer channel, wherein the outer channel surrounds the middle channel, wherein the outer channel is electrically insulated from the middle channel, wherein the device is configured for flowing a second ignitable gas through the outer channel towards an exit opening of the outer channel; and
a nozzle cap, wherein the nozzle cap encloses a mixing volume located after the exit openings of the inner channel, the middle channel and the outer channel, and wherein the nozzle cap is provided with an exit opening after the mixing volume, wherein the exit opening of the nozzle cap is smaller than the exit opening of the outer channel.