Examination of the Binding Mechanism of Mercury in Fluorescent Lamp Coatings

ABSTRACT

The mercury consumption during the operation of fluorescent lamps is not entirely understood. There are no publications that have reported in which chemical state the mercury is bound in alumina precoats. In the present study, alumina precoat lamps without a phosphor coating were built and seasoned for up to 8400 h. Parts from the seasoned lamps were analyzed using X-ray photoelectron spectroscopy (XPS) und thermal desorption mass spectrometry (TDMS). It could be shown that the state of the chemical binding of the mercury atoms changes with seasoning time. It appears that mercury is deposited in a zero-valent binding state that changes to an HgO-like binding state with increased seasoning time of the lamp.

KEYWORDS:

• fluorescent lamp
• mercury consumption
• thermal desorption
• XPS

Additional information

Funding

This work was funded by the Bayerische Forschungsstiftung within the Bavarian research cooperation for Multi Scale Design of Functional Oxidic Materials (FOROXID).