An asymmetric bis-silane compound of the formula A.sub.3Si--R.sup.1--SiB.sub.3 where A, B, and R.sup.1 are as defined herein, and to methods for making the bis-silane compound and their use to form layers or films of metal oxide particles, and which layers or films adhere to a suitable substrate. The materials and methods can be used, for example, to make photoactive devices.