The present invention relates generally to nanotechnology and sub-microelectronic circuitry, and more particularly to nanoelectronics. One aspect of the invention is directed to nanostructures on substrates. In some cases, the substrate may be or comprise glass and/or polymers, and in some cases, the substrate may be flexible and/or transparent. The present invention is also directed, according to another aspect, to techniques for fabricating nanostructures on substrates. For example, monolayers of nanoscale semiconductors may be etched, e.g. photolithographically, to yield discrete and/or predetermined arrays of nanoscale semiconductors and other articles on a substrate. In one embodiment, the array may include hundreds, thousands, or more of electronic components such as field-effect transistors. Such arrays may be connected to electrodes using photolithographic techniques, and in some cases, without the need for registering individual semiconductor-metal contacts.