新型电子阻挡层结构对蓝光InGaN发光二极管性能的提高

分别对3种不种电子阻挡层的蓝光AlGaN LED进行数值模拟研究。3种阻挡层结构分别为传统AlGaN电子阻挡层,AlGaN-GaN-AlGaN电子阻挡层和Al组分渐变的AlGaN-GaN-AlGaN电子阻挡层。此外对这对三种器件的活性区的载流子浓度、能带图、静电场和内量子效率进行比较和分析。研究结果表明,相较于传统AlGaN和AlGaN-GaN-AlGaN两种电子阻挡层的LED,具有Al组分渐变的AlGaN-GaN-AlGaN电子阻挡层结构的LED具有较高的空穴注入效率、较低的电子外溢现象和较小的静电场(活性区)。同时,具有Al组分渐变的AlGaN-GaN-AlGaN电子阻挡层结构的LED的efficiency droop现象也得到一定的缓解。     

Performance improvement of blue InGaN light-emitting diodes with a specially designed n-AlGaN hole blocking layer

Blue InGaN light-emitting diodes (LEDs) with a conventional electron blocking layer (EBL), a common n-AlGaN hole blocking layer (HBL), and an n-AlGaN HBL with gradual Al composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency (IQE). The results indicate that LEDs with an n-AlGaN HBL with gradual Al composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conventional p-AlGaN EBL or a common n-AlGaN HBL. Meanwhile, the efficiency droop is alleviated when an n-AlGaN HBL with gradual Al composition is used.     

Performance improvement of GaN-based light-emitting diode with a p-InAIGaN hole injection layer

The characteristics of a blue light-emitting diode （LED） with a p-InA1GaN hole injection layer （HIL） is analyzed numerically. The simulation results indicate that the newly designed structure presents superior optical and electrical performance such as an increase in light output power, a reduction in current leakage and alleviation of efficiency droop. These improvements can be attributed to the p-InA1GaN serving as hole injection layers, which can alleviate the band bending induced by the polarization field, thereby improving both the hole injection efficiency and the electron blocking efficiency.     

Performance improvement of GaN-based light-emitting diode with a p-InAlGaN hole injection layer

The characteristics of a blue light-emitting diode(LED)with a p-InAlGaN hole injection layer(HIL)is analyzed numerically.The simulation results indicate that the newly designed structure presents superior optical and electrical performance such as an increase in light output power,a reduction in current leakage and alleviation of efficiency droop.These improvements can be attributed to the p-InAlGaN serving as hole injection layers,which can alleviate the band bending induced by the polarization field,thereby improving both the hole injection efficiency and the electron blocking efficiency.     

光散射PC荧光树脂的制备及光学性能

以聚碳酸酯(PC)粉体、有机硅光扩散剂和YAG∶Ce荧光粉为原料,通过熔融共混法和高温压模法及减薄抛光工艺制备出不同有机硅光扩散剂质量分数的PC/YAG∶Ce光散射荧光树脂样品,通过SEM、XRD、透射光谱和PL的性能分析,表明：荧光树脂样品在500～800 nm光谱范围有较高的透光率,样品的主相都为Y₃Al₅O₁₂,在342和448 nm有两个激发波峰,发射光谱在532 nm有一宽峰,属于Ce3+的5d→4f特征跃迁发射,对应的荧光寿命在61.5 ns左右。把荧光树脂样品应用到白光LED器件的封装获得的光效为81.12 lm/W@100 mA, 说明PC/YAG∶Ce荧光树脂片适用于作白光LED封装的新型荧光材料。     

Performance improvement of blue InGaN light-emitting diodes with a specially designed n-AIGaN hole blocking layer

Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.