Gu Fuxing, Wang Pan, Yu Huakang, Guo Bing, Tong Limin
State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University, Hangzhou 310027, China.
Opt Express. 2011 May 23;19(11):10880-5. doi: 10.1364/OE.19.010880.
We demonstrate broadband optical quenching of photoconductivity in CdSe single nanowires with low excitation power. Using 1550-nm-wavelength light with 10-nW power for waveguiding excitation, we observe a typical responsivity of 0.5 A/W for quenching the photoconductivity established by 10-µW 660-nm-wavelength background light in a 403-nm-diameter CdSe nanowire, with detectable limit of the quenching power down to pW level at room temperature, which is several orders of magnitude lower than those reported previously. This large quenching effect originates from the enhanced light-defect interaction in the nanowires via waveguiding excitation. These results open new opportunities for noninvasive characterization of deep-level defect states in low-dimensional semiconductor nanomaterials, and novel optoelectronic applications of semiconductor nanowires such as high-sensitive broadband photodetection.
我们展示了在低激发功率下对CdSe单纳米线光导率的宽带光学猝灭。使用功率为10 nW、波长为1550 nm的光进行波导激发，我们观察到在直径为403 nm的CdSe纳米线中，对于猝灭由10 µW、波长为660 nm的背景光所建立的光导率，典型响应度为0.5 A/W，在室温下猝灭功率的可检测极限低至皮瓦级别，这比之前报道的低几个数量级。这种大的猝灭效应源于通过波导激发增强了纳米线中的光-缺陷相互作用。这些结果为低维半导体纳米材料中深层缺陷态的非侵入性表征以及半导体纳米线的新型光电子应用（如高灵敏度宽带光探测）开辟了新机遇。
