Abstract: A field effect transistor (20) for chemical sensing, comprising an electrically conducting and chemically sensitive channel (2) extending between drain (5) and source (6) electrodes. A gate electrode (7) is separated from the channel (2) by a gap (10) through which a chemical to be sensed can reach the channel (2) which comprises a continuous monocrystalline graphene layer (2a) arranged on an electrically insulating graphene layer substrate (1). The graphene layer (2a) extends between and is electrically connected to the source electrode (5) and the drain electrode (6). The substrate supports the graphene layer, allowing it to stay 2-dimensional and continuous, and enables it to be provided on a well defined surface, and be produced and added to the transistor as a separate part. This is beneficial for reproducibility and reduces the risk of damage to the graphene layer during production and after. Low detection limits with low variability between individual transistors are also enabled.

Abstract: The present disclosure relates to a process for growth of graphene at a temperature above 1400° C. on a silicon carbide surface by sublimation of silicon from the surface. The process comprises heating under special conditions up to growth temperature which ensured that the surface undergoes the proper modification for allowing homogenous graphene in one or more monolayers.

Abstract: A field effect transistor (20) for chemical sensing, comprising an electrically conducting and chemically sensitive channel (2) extending between drain (5) and source (6) electrodes. A gate electrode (7) is separated from the channel (2) by a gap (10) through which a chemical to be sensed can reach the channel (2) which comprises a continuous monocrystalline graphene layer (2a) arranged on an electrically insulating graphene layer substrate (1). The graphene layer (2a) extends between and is electrically connected to the source electrode (5) and the drain electrode (6). The substrate supports the graphene layer, allowing it to stay 2-dimensional and continuous, and enables it to be provided on a well defined surface, and be produced and added to the transistor as a separate part. This is beneficial for reproducibility and reduces the risk of damage to the graphene layer during production and after. Low detection limits with low variability between individual transistors are also enabled.

Abstract: The present disclosure relates to a process for growth of graphene at a temperature above 1400° C. on a silicon carbide surface by sublimation of silicon from the surface. The process comprises heating under special conditions up to growth temperature which ensured that the surface undergoes the proper modification for allowing homogenous graphene in one or more monolayers.

Abstract: A method of producing an epitaxial layer on a substrate of silicon carbide is provided. Utilizing the system, silicon carbide can be grown with a thickness uniformity that is better than 5% at a growth rate which is at least 100 ?m/hour. The method comprises providing a cavity with a source material and a substrate of monolithic silicon carbide, evacuating the cavity and raising the temperature to 1400° C. Then the temperature is increased at a rate of about 20° C./min until a predetermined growth temperature is reached. Thereafter, the temperature is kept such that a predetermined growth rate between 10 ?m/min and 300 ?m/min is obtained.

Abstract: A method of producing an epitaxial layer on a substrate of silicon carbide is provided. Utilizing the system, silicon carbide can be grown with a thickness uniformity that is better than 5% at a growth rate which is at least 100 ?m/hour. The method comprises providing a cavity with a source material and a substrate of monolithic silicon carbide, evacuating the cavity and raising the temperature to 1400° C. Then the temperature is increased at a rate of about 20° C./min until a predetermined growth temperature is reached. Thereafter, the temperature is kept such that a predetermined growth rate between 10 ?m/min and 300 ?m/min is obtained.