ICANS 25, the 25th International Conference on Amorphous and Nanocrystalline Semiconductors, which is a biennial conference, has been the premier conference in the area of amorphous semiconductors and related materials, including organic and oxide semiconductors. Although its origins were mainly in amorphous and liquid semiconductors dating back to 1965 (Prague), in its present form it covers a broader range of materials, including nanocrystalline and organic semiconductors. The topics range from the physics and chemistry of fundamental phenomena to the engineering of materials and devices. In the last fifteen years microcrystalline and nanocrystalline semiconductors have become a key-component of this conference, and has complemented the traditional focus on amorphous thin films such as hydrogenated Si (a-Si:H) and chalcogenides glasses. In addition, in the last ten years, the conference has featured key sessions on amorphous and nanocrystalline oxide and organic semiconductors, and phase change memory materials. Sessions on film growth mechanisms, medium-range order, defects, metastability, electronic transport, optical properties, sensors, TFTs, and photoltaics provide opportunities for cross-fertilization among researchers working on diverse material systems and applications.