中国物理B ›› 2010, Vol. 19 ›› Issue (11): 114210-114301.doi: 10.1088/1674-1056/19/11/114210
Gopal Achanta Venu1, 刘正奇2, 冯天华2, 戴峭峰2, 吴立军2, 兰胜2, 丁才蓉3, 汪河洲3
Liu Zheng-Qi(刘正奇)a), Feng Tian-Hua(冯天华) a), Dai Qiao-Feng(戴峭峰)a), Wu Li-Jun(吴立军)a), Lan Sheng(兰胜)a)†, Ding Cai-Rong(丁才蓉)b), Wang He-Zhou(汪河洲)b), and Gopal Achanta Venuc)
摘要: This paper demonstrates experimentally and numerically that a significant modification of spontaneous emission rate can be achieved near the surface of a three-dimensional photonic crystal. In experiments, semiconductor core-shell quantum dots are intentionally confined in a thin polymer film on which a three-dimensional colloidal photonic crystal is fabricated. The spontaneous emission rate of quantum dots is characterised by conventional and time-resolved photoluminescence (PL) measurements. The modification of the spontaneous emission rate, which is reflected in the change of spectral shape and PL lifetime, is clearly observed. While an obvious increase in the PL lifetime is found at most wavelengths in the band gap, a significant reduction in the PL lifetime by one order of magnitude is observed at the short-wavelength band edge. Numerical simulation reveals a periodic modulation of spontaneous emission rate with decreasing modulation strength when an emitter is moved away from the surface of the photonic crystal. It is supported by the fact that the modification of spontaneous emission rate is not pronounced for quantum dots distributed in a thick polymer film where both enhancement and suppression are present simultaneously. This finding provides a simple and effective way for improving the performance of light emitting devices.
中图分类号: (Photonic bandgap materials)