Transient preconditioning in CIGS solar cells and modules

Transient preconditioning refers to a light induced performance change in CIGS which occurs and relaxes on a millisecond to seconds timescale. This effect appears to be distinct from the better known and more persistent preconditioning which typically takes several hours or days to relax. In this paper some properties of this phenomenon are explored including the variation of if the effect with voltage and temperature. The consequences for repeatable and accurate device measurement are explored. In particular the transient rise in photocurrent during measurements using a pulsed simulator can be successfully eradicated using voltage preconditioning when there is no gap between the preconditioning voltage being applied and the start of the illumination pulse.