Technical Note - LP980

This Technical Note is written to show customers how to properly align and measure solid samples using the LP980 Transient Absorption Spectrometer when equipped with the diffuse reflection accessory.

In this technical note we explore Transient absorption (flash photolysis), which is a powerful tool to understand many photochemical properties and reactions, from measuring the energy levels and lifetimes of excited singlet and triplet states, to measuring electron and energy transfer rates of paired molecular systems, and even photocatalysis intermediates and products.

In flash photolysis, a short pulse of light generates a transient (temporary) species in a sample; e.g. a radical intermediate or a short-lived excited state. As the sample relaxes back to the ground state or the final reaction products, the changes occurring are recorded as a function of time using a spectroscopic technique. A flash photolysis spectrometer typically monitors the change in absorption as a function of time, utilising a second light source (probe) besides the excitation (pump) pulse going through the sample. This technique is also known as transient absorption (TA). This technical note is aimed as an introduction to nanosecond flash photolysis for newcomers to the technique. We describe the operation of the LP980 spectrometer and show examples of measurements, with references to real-life applications.