High temperature semiconductor devices having at least one gallium nitride layer

A semiconductor power transistor comprising:

• a p-type silicon carbide layer having a first surface;
• a first n-type gallium nitride layer deposited on said first surface;
• said p-type silicon carbide layer having an energy gap that is substantially less than that of said first gallium nitride layer and having a second surface opposite said first surface;
• a second n-type gallium nitride layer in contact with said second surface, said second n-type gallium nitride layer forming a pn heterojunction with said second surface;
• and
• said p-type silicon carbide layer being the base of said power transistor and said n-type gallium nitride layers being the emitter and the collector of said power transistor.

A semiconductor photovoltaic direction-sensing device, comprising:

• a first layer made of p-type gallium arsenide having opposite surfaces for receiving radiation from first and second different directions;
• a second layer made of n-type gallium nitride formed on one of said opposite surfaces;
• a first pn heterojunction between said first layer and said second layer;
• said second layer being transparent for allowing the radiation from said first direction to be received on said first pn heterojunction to generate a photovoltage having a first polarity indicating response to the radiation from said first direction;
• a third layer made of n-type gallium nitride formed on the other of said opposite surfaces;
• a second pn heterojunction between said first layer and said third layer;
• said third layer being transparent for allowing the radiation from said second direction to be received on said second pn heterojunction to generate a photovoltage having a second polarity indicating response to the radiation from said second direction;
• and
• metal electrodes contacting each said second and third respective layers for extracting said photovoltages externally of said device.

A semiconductor photovoltaic direction-sensing device having high temperature operating characteristics, comprising:

• a first layer of p-type cubic silicon carbide having opposite surfaces for receiving radiation from first and second different directions;
• a second layer of n-type cubic gallium nitride formed on one of said opposite surfaces;
• a first pn heterojunction between said first layer and said second layer;
• said second layer being transparent for allowing the radiation from said first direction to be received on said first pn heterojunction to generate a photovoltage having a first polarity indicating response to the radiation from said first direction;
• a third layer made of n-type cubic gallium nitride formed on the other of said opposite surfaces;
• a second pn heterojunction between said first layer and said third layer;
• said third layer being transparent for allowing the radiation from said second direction to be received on said second pn heterojunction to generate a photovoltage having a second polarity indicating response to the radiation from said second direction;
• and
• metal electrodes contacting each said second and third respective layers for applying said photovoltages externally of said device to indicate the direction from which the radiation is incident on said device.

A semiconductor photovoltaic position sensing comprising:

• a first layer made of p-type silicon carbide and having a first surface, said first surface having a first area and a second area, said first area being adapted to receive radiation from a first position, said first area being spaced from said second area of said first surface, said second area being adapted to receive radiation from a second position;
• a second layer made of n-type gallium nitride and being on said first area for forming a first pn heterojunction with said first silicon carbide layer, said second layer being transparent for allowing the radiation from said first position to be received on said first pn heterojunction to generate a first photovoltage for indicating the radiation from said first position;
• and
• a third layer made of n-type gallium nitride and being on said second area for forming a second pn heterojunction with said first silicon carbide layer, said third layer being transparent for allowing the radiation from said second position to be received on said second pn heterojunction to generate a second photovoltage for indicating the radiation from said second position.

A semiconductor photovoltaic position sensing device, comprising:

• a first layer made of p-type gallium arsenide and having a first surface, said first surface having a first area for receiving radiation from a first position, said first area being spaced from a second area of said first surface for receiving radiation from a second position;
• a second layer made of n-type gallium nitride and being on said first area for forming a first pn heterojunction with said first gallium arsenide layer, said second layer being transparent for allowing the radiation from said first position to be received on said first pn heterojunction to generate a first photovoltage for indicating the radiation from said first position;
• and
• a third layer made of n-type gallium nitride and being on said second area for forming a second pn heterojunction with said first gallium arsenide layer, said third layer being transparent for allowing the radiation from said second position to be received on said second pn heterojunction to generate a second photovoltage for indicating the radiation from said second position.