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在温度变化时,如果GaInN发光二极管能够保持相对稳定的工作电压对其实际应用具有重要意义.本文通过金属有机化学气相沉积生长了一系列包含不同有源区结构、不同p型层结构以及不同掺杂浓度纵向分布的样品,并对其在不同温度区间内正向电压随温度变化的斜率(dV/dT)进行了研究.结果表明:1)有源区中包括插入层设计、量子阱结构以及发光波长等因素的变化对正向电压随温度变化特性影响很小;2)影响常温区间(300K±50K)正向电压随温度变化斜率的最主要因素为p-AlGaN电子阻挡层起始生长阶段的掺杂形貌,具有p-AlGaN陡掺界面的样品电压变化斜率为-1.3mV·K-1,与理论极限值-1.2mV·K-1十分接近;3)p-GaN主段层的掺Mg浓度对低温区间(<200K)的正向电压随温度变化斜率有直接影响,掺Mg浓度越低则dV/dT斜率越大.以上现象归因于在不同温度区间,p-AlGaN以及p-GaN发生Mg受主冻结效应的程度主要取决于各自的掺杂浓度.因此Mg掺杂浓度纵向分布不同的样品在不同的温度区间具有不同的串联电阻,最终表现为差异很大的正向电压温度特性.
When the temperature changes, if the GaInN LED can maintain a relatively stable operating voltage, it is of great significance for its practical application.In this paper, a series of different structures containing different active region structures, different p-type layer structures and different doping levels were grown by metalorganic chemical vapor deposition (DV / dT) of forward voltage with temperature in different temperature ranges were studied.The results show that: 1) the active region includes the design of the insertion layer, the quantum well structure and (2) The most important factor that affects the slope of forward voltage with temperature at room temperature (300K ± 50K) is the initial growth phase of p-AlGaN electron blocking layer The slope of the sample with a p-AlGaN abrupt interface is -1.3mV · K-1, which is close to the theoretical limit of -1.2mV · K-1. 3) The doping concentration of Mg has a direct effect on the slope of the temperature in the low temperature range (<200K), and the slope of dV / dT increases with the decrease of the doping concentration of Mg.The above phenomenon is attributed to the increase of p-AlGaN and p -GaN Mg host freezing effect occurs The extent depending on their dopant concentration. Thus Mg doping concentration profile longitudinal sections of different samples with different series resistance at different temperatures, the final performance of very different forward voltage temperature characteristic.