Quasi-periodic arrays of quantum dots and nanowires of a wide variety of materials can be self-assembled using simple beaker electrochemistry. The chemistry controls the size, density and material composition. In terms of periodicity, size control, cost, and achievable nanostructure density, electrochemical self-assembly more than rivals others such as Stranski-Krastanow growth. However, because of the wet chemistry employed, the material purity is compromised. Nonetheless, these structures show intriguing device behavior. Here, we describe a unique device-a room-temperature infrared photodetector that also exhibits a negative differential resistance. The amplitude and position of the NDR peak can be modulated by infrared excitation. This may have application in biologically inspired computing architectures. (C) 2004 Elsevier B.V. All rights reserved.