Apr 15 2009
Andor Technology plc (Andor), a world leader in scientific imaging and spectroscopy solutions, has applied Electron Multiplying (EM) technology for the first time to dramatically improve both the speed and sensitivity of Scanning Tunnelling Luminescent spectroscopy (STL) by replacing the standard CCD camera, used to detect photons, with one of its Electron Multiplying CCD (EMCCD) cameras. This improves the signal to noise ratio and cuts the time required to gather meaningful low light emission spectral data.
Reducing the exposure times typically associated with STL, will also solve some of the common problems associated with this technique, including changes in the tip-sample cavity, through the migration of tip or sample atoms or contamination, and damage to the sample caused by excessive tunnelling current applied over a prolonged time period.
Using EMCCD Andor cameras such as the Newton(EM) model in conjunction with high performance Shamrock spectrographs from Andor will make STL a far more useful technique for applications such as characterising nano-photonic and optoelectronic devices and their structures, ultra-sensitive chemical analysis, single molecule optical spectroscopy, single molecule dynamics and conformational analysis, luminescence studies on Quantum wells/dots, intermolecular fluorescence studies and electronic dynamics in polymers and bio-molecules.
Commenting on the application of new technology to an established technique, Gerald Cairns, Spectroscopy Application Specialist at Andor said, “Although STL spectroscopy is a very useful technique for generating information about the topography and structure of a sample, and the chemistry of any absorbed molecules, the very low light signals generated have necessitated the use of very long exposure times, typically several minutes. However, the enhanced sensitivity and higher acquisition speeds of our EMCCD cameras means that spectral data can now be acquired far faster and with less background noise. This will help broaden the utility of STL and help increase our understanding of nano- and micro-scale optoelectronic and photonic devices”.