3results about How to "Increase the bandgap width" patented technology

The utility model relates to a kind of LED epitaxial structures, comprising: substrate;N type layer;Active layer is located on N type;P type layer, located on active layer;Wherein, the P type layer includes P type window layer, P type window layer includes several first laminated structure, each first laminated structure includes the GaInP layer, first GaP layer and second GaP layer of sequentially laminated, the P type doping concentration of second GaP layer in each first laminated structure is greater than the P type doping concentration of first GaP layer.The GaInP layer of the utility model has higher band gap, plays the role of optical window layer, can reduce light absorption loss;GaP has lower band gap, first GaP layer and second GaP layer play the role of buffer layer / transition layer, so the combination of GaInP layer, first GaP layer and second GaP layer realizes the balance of band matching and carrier transport efficiency, conducive to the efficient extension of current.

The embodiment of the invention provides projection equipment, a laser television and a vehicle, the projection equipment comprises an MEMS galvanometer chip, the MEMS galvanometer chip adopts silicon carbide as a chip substrate, and compared with a silicon-based chip, the silicon carbide has the characteristics of high thermal conductivity, high forbidden band width and the like, and the MEMS galvanometer chip has the advantages of high thermal conductivity and high forbidden band width. According to the MEMS galvanometer chip, the rotating suspension beam integrated with the mirror surface in the projection equipment using the MEMS galvanometer chip is not easy to damage at high temperature and low in heat dissipation requirement, the problems caused by working temperature rise such as fusing of the rotating suspension beam are avoided, the projection equipment has better environment adaptability, the heat dissipation requirement is low, the heat dissipation structure can be reduced, and the projection equipment is more miniaturized.

A method for preparing and applying a cross-linked network polyimide composite material based on electron-withdrawing groups is disclosed, relating to the field of high-temperature energy storage technology for electrolyte capacitors. Method: 3,5-tris(4-amino-2-trifluoromethylphenoxy)benzene is added to a polyimide colloidal solution and stirred uniformly under a nitrogen atmosphere to obtain solution b; solution b is evacuated and then uniformly coated onto one side of a pretreated substrate. After curing, the substrate is subjected to gradient heating, and finally the film on the substrate is peeled off to obtain the cross-linked network polyimide composite material based on electron-withdrawing groups; the application of the cross-linked network polyimide composite material based on electron-withdrawing groups in dielectric capacitors. This invention provides a method for preparing and applying a cross-linked network polyimide composite material based on electron-withdrawing groups.