The thesis mainly probes into the effects that the structure below multi quantum layer as regards the efficiency of luminescence of blue light LED in the different number layers and make further comparison. In the article, the students separately make analysis and comparison to the single quantum well , five multi quantum wells , ten multi quantum wells and thirty multi quantum wells. And discovered that different number layers of quantum well will occur different Phase Separation and Strain in the film. So the article mainly focuses on : (1.)Phase Separation in various of quantum well, it occurs different In-rich reaction and (2.)Different Strain levels which occurs different dislocation reaction. The two mechanisms will be discussed in detail with the effects of luminescence reaction of LED. According to the results of experiment, We found that it is easier to form V-shape defects and dislocation with the increasing indium content. Under the high indium content, the density of In-rich will increase obviously and spread to the GaN barrier, then the original structure of quantum well will be destroyed and descend the efficacy of luminescence. In the thicker GaInN quantum well, it will induce larger energy of strain inside the film, So the defect density will increase due to release the strain energy. It was also discovered the intensity of luminescence descend after measuring by PL. When grow different number layers , it was discovered that higher quantum layer will produce the roughness surfaces when using AFM . So the higher quantum layers will make greater influence in the efficacy of luminescence. By experiment, we found that the five to ten quantim wells will have the better photo characteristic.

GaInN has the potential to revolutionize the solar cell industry, enabling higher efficiency solar cells with its wide bandgap range spanning the entire solar spectrum. However, material quality issues stemming from the large lattice mismatch between its binary endpoints and questionable range of p-type doping has thus far prevented realization of high efficiency solar cells. Nonetheless, amorphous and multi-crystalline forms of GaInN have been theorized to exhibit a defect-free bandgap, enabling GaInN alloys at any indium composition to be realized. But the range of possible p-type doping has not yet been determined and no device quality material has been demonstrated thus far. Nonetheless, a Schottky barrier design (to bypass the p-type doping issue) on single-crystal GaInN can be used to provide some insight into the future of amorphous and micro-crystalline GaInN Schottky barrier solar cells. Through demonstration of a functional single crystalline GaInN Schottky barrier solar cell and comparison of the results to the best published reports for more conventional p-i-n GaInN solar cells, this work aims to establish the feasibility of amorphous and multi-crystalline GaInN solar cells. / Ph. D.