The grain structure of CSS-deposited CdTe/CdS solar cells was studied as a
function of annealing time in the presence of CdCl2. The structure was stud
ied by chemically bevelling the cell to reveal the grains at all depths of
the layer. The grain boundaries were revealed using a defect sensitive etch
, and photomicrographs taken at intervals down the bevel. These photomicrog
raphs were then analysed computationally. Histograms of grain radius for ea
ch micrograph were fitted well by the Rayleigh distribution. The average gr
ain radii were found to vary linearly throughout the CdTe layer as (r) over
bar = (0.107 x d) + 1.06, where d is the distance from the interface. This
behaviour was unaffected by the CdCl2 treatment and is discussed with refe
rence to a kinetic model of grain growth. Finally the use of correlation pl
ots in analysing grain centroid distribution is described and some results
presented. (C) 2000 Elsevier Science S.A. All rights reserved.