STUDY OF THE ACTIVE LAYER IN HYDROGENATED AMORPHOUS-SILICON SOLAR-CELLS USING ELECTRICAL AND ANALYTICAL TECHNIQUES

An attempt was made to understand the distribution of defect states in the active layers of p-i-n hydrogenated amorphous silicon solar cells . Capacitance-Voltage (CV) measurements were used to study the defect distribution in the i-layer, both in the bulk as well as near the p-i interface for cells fabricated on different substrates. The effect of inserting a buffer layer between the p and i-layers were also investig ated. A combination of secondary ion mass spectroscopy (SIMS), seconda ry neutral mass spectroscopy (SNMS) and electron spectroscopy for chem ical analysis (ESCA) measurements were used to study the elemental dis tribution in the active layer, specially those of the elements for the neighbouring p and transparent conducting oxide (TCO) layers. The X-r ay, electron and ion beam probes when combined with the electrical ana lysis not only help to determine the cell structure resulting in optim um i-layer performance (both near the p-i interface and the bulk) but also gave an indication of the desired growth conditions of the i-laye r.