34 results about "Quantum tunnelling" patented technology

The invention discloses a light-emitting diode epitaxial wafer with high luminous efficiency and a preparation method thereof, belonging to the field of light-emitting diodes. The high-luminous-efficiency light-emitting diode epitaxial wafer includes: a substrate, and a u-type GaN layer, an N-type GaN layer, a multi-quantum well active layer, a P-type AlGaN layer, and a P-type GaN carrier layer covering the substrate in sequence , the multi-quantum well active layer includes a plurality of InGaN well layers and a plurality of GaN barrier layers grown alternately; the P-type AlGaN layer includes the first P-type AlGaN sublayer, u-type GaN sublayer and the second P-type AlGaN sublayer. It can not only reduce the potential energy required for holes in the P-type GaN carrier layer to cross the P-type AlGaN layer, but also form a quantum state in the u-type GaN sublayer. The potential energy in the P-type GaN carrier layer is lower than that of crossing the P-type The holes with the potential energy required by the AlGaN layer will tunnel into the u-type GaN sub-layer through the quantum tunneling effect, and then be transported into the quantum wells, increasing the hole concentration injected into the multi-quantum well active layer.

The invention discloses a graphene strip heterojunction double-gate TFET and a method for improving switching characteristics thereof. How to improve the on-state current of TFET is an important direction of TFET research. The source region, the drain region and the channel between the source region and the drain region of the present invention form a graphene strip heterojunction; the channel is composed of a first channel section and a second channel section arranged along the direction from the source region to the drain region ; The source region, the second section of the channel and the drain area are all armchair graphene nano-strips; the extending direction of the strips of the first channel and the extending direction of the armchair graphene nano-strips form an included angle. In the off state of the present invention, a section of the channel is a bandgap armchair graphene nano-strip along the length direction of the device, and the regional density of states is 0, which plays a role in suppressing the off-state current; in the on state, there is Current, one section of the channel is a zigzag graphene strip along the direction of current transmission, and there is no band gap in one section of the channel, which promotes the quantum tunneling effect of electrons between the source region and the channel, and increases the on-state current.