THE RESEARCH OF QUENCHING EFFECT IN GRADIENT-BANDGAP CdSSe NANOWIRE

Quenching effect of photoconductive semiconductor material has important applications in areas like detecting semiconductor defect and infrared light. In this paper, vapor–liquid–solid (VLS) method is improved to grow nanowires by using a heat resisting quartz tube as the vessel. With the conditions of gold catalysis, appropriate temperature, and ease of handling, gradient-bandgap CdSSe nanowires were grown successfully. We study the quenching effect of different component parts of the nanowire, respectively, and find that the quenching degree increases with the increasing optical intensities of different bandgap nanowires when the power injection is below 10−8W. However, since more recombination centers would turn into the trap energy level centers leading to more electrons to jump into the conduction band with the increasing density of CdS, the peak of quenched rate for 90% CdS proportion nanowire arrives earlier than 90% CdSe proportion, and the peak of quenched rate for CdSe still does not appear even when the optical intensity reaches 10−6W. Our experiment provides an effective and convenient method for the defect-level detection of semiconductor materials, and can also develop high resolution infrared detectors under the material limitation conditions.