A method is disclosed for tightening laces of an article of clothing. To reduce high interface recombination at the substrate surface, the nano-particle emitters are preferably formed over a thin interfacial tunnel oxide layer on the surface of the substrate. Both apparatus and method embodiments are described. The control circuit comprises a control comparator that is coupled at a first input with a signal output of the driver circuit and at an output with the feedback input and also to which, at a second input, a reference signal can be fed. The scripts may invoke an editor, such as the Unix stream editor, to bind the tagged DDL code to specific system parameters.