A group of scientists under the leadership of Professor Alexander Holleitner, a member of the Cluster of Excellence Nanosystems Munich, and a physicist at the Technische Universitaet Muenchen, have developed a new speed measurement technique of time-resolved photocurrent in photodetectors with picosecond accuracy.
Alexander Holleitner has stated that one picosecond is a very less interval of time. He mentioned that electrons moving at the speed of light can almost reach the moon within a second and in a picosecond they would have moved just one third of a millimeter.
The new method is around hundred times quicker than the other methods. It enables researchers to determine the accurate speed of electrons. In one picosecond the electrons can travel just 800 nanometers inside the carbon nanotubes.
The physicists determined the speed of electrons in carbon tubes with one nanometer of diameter straddling a small gap amid two gold detectors. They used an exclusive time-resolved laser spectroscopy technique termed as the pump-probe method. It functions by stimulating electrons in the carbon nanotube using laser pulse and monitoring the process dynamics by means of a second laser.
The perceptions and investigative opportunities offered by this new method are applicable to several applications in the areas of optoelectronic parts like photo-switches, nanoscale photodetectors and solar cells.
Major sponsors of the research include the German Research Foundation (Cluster of Excellence Nanosystems Initiative Munich, NIM) and the Center for NanoScience (CeNS). Other sponsors include the Swiss Federal Institute of Technology and physicists of the University of Regensburg.