Combinatorial approaches have become very powerful tools for discovering and optimizing new materials and devices. Increasing the experimental efficiency, i.e. the experimental throughput, is one of the central motivations for switching to a combinatorial approach. In this paper, the application of the combinatorial approach to researching amorphous-silicon-based materials and devices is demonstrated. Thin-film materials that gradually transition from amorphous to microcrystalline (muc) silicon with various hydrogen dilutions have been successfully, and rapidly, deposited on a single substrate using the hot-wire chemical vapor deposition technique. It is worth noting that no time is wasted in between loading, vacuuming, and heating the samples. Also, many thicknesses graded stripes can be grown on a substrate, allowing study of the thickness-dependent growth of the muc-Si. For device applications such as solar cells, the combinatorial approach can fabricate the solar cell in a way that permits rapid optimization of p-type, intrinsic, and n-type layers within the device structure. Also, a combination of n-, i- and players allows the study of each layer as well as the combinations of each layer on a single substrate. Based on this initial study, the combinatorial approach has speeded up the rate of experimentation by at least a factor of 10. Additional increases ranging from 10 to 100 are foreseeable with the aid of computer control and automations. (C) 2003 Elsevier Science B.V. All rights reserved.