摘要
量子阱红外探测器发光二极管(Quantum Well Infrared Photodetector Light Emitting Diode,QWIP-LED)是一种新型红外上转换器件,配合电荷耦合器件(Charge Coupled Device,CCD)能够实现中波红外成像探测。与常规红外成像器件相比,QWIP-LED最大的优势在于成本低。然而,QWIP-LED较低的光提取效率(约2%)严重制约了该器件的广泛应用。以提高QWIP-LED的光提取效率为目标,在LED表面引入二维光子晶体薄膜(Photonic Crystal Slab,PCS)结构,采用时域有限差分法(Finite-Difference Time-Domain,FDTD)计算了其对光提取效率的改善效果,并对PCS的结构参数进行了优化。仿真结果表明,优化的PCS可以使QWIP-LED的光提取效率提高2.32倍。最后,基于PCS的能带理论以及等效介质理论,对PCS结构提高器件光提取效率的机理进行了分析。
A Quantum Well Infrared Photodetector Light Emitting Diode （QWIP-LED） is a new infrared up-converter. When combining with a Charge Coupled Device （CCD）, it can be used for mid-wave infrared imaging detection. Compared with the conventional infrared imaging devices, QWIP-LEDs have a remarkable advantage of low cost. However, because of the low light extraction efficiency （~2%）, their application is limited. To improve the light extraction efficiency of the QWIP-LED, a Photonic Crystal Slab （PCS） is incorporated into the surface of the LED. Then, a Finite Difference Time Domain （FDTD） method is used to calculate the improved light extraction efficiency, so as to optimize the structure parameters of the PCS. The simulation result shows that by using an optimized PCS, the light extraction efficiency of the QWIP-LED can be increased by a factor of 2.32. Finally, the mechanism for the PCS to increase light extraction efficiency is analyzed according to the band theory and equivalent medium theory.
出处
《红外》
CAS
2014年第4期13-17,44,共6页
Infrared
